HELP! Sudden, dramatic browsing slowdown!

Posted by: droogie

HELP! Sudden, dramatic browsing slowdown! - 09/30/08 04:34 PM

I have 4 Macs and one PC on an Airport wireless network, and the fastest DSL connect the company offers. Until last week the browsing speed on the main business iMac upstairs in my office (and all other Macs, and PC, on the network) was absolutely blazing fast.<br><br>All of a sudden -- and seemingly out of nowhere -- the browsing speed of the main office iMac has not only slowed dramatically, but almost come to a crawl. Here are some facts:<br><br> Browsing on all other comps on the network remain blazing fast, as usual<br> Download speeds on the problematic iMac remain as fast as before this problem started. Only web browsing, using any and ALL browsers (Safari, Firefox, etc.) seems to exhibit the problem. Although, there is a rather significant pause before downloads actually proceed.<br> I hadn't downloaded/installed any new software from any source prior to the problem starting<br> The irritating pause before downloads commence is also evident when attempting to load web pages<br> Even text-based pages load agonizingly slow... and load completely only after minutes have expired... the same pages used to completely load in seconds, if not instantaneously!<br><br>There are other problems, but I think you get the point.<br><br>Again, no other computer exhibits this behavior when browsing or otherwise, and the offending iMac exhibits the behavior ONLY when browsing... not when downloading, streaming content or any other speed-related duty.<br><br>I've tried clearing browser cache, history, trashing certain net-related prefs. I've used three different Virus scans and there are no viruses or spyware-related files on the comp (it is acting kinda' like it has a virus... although a virus wouldn't affect only browser speed). I've checked my disk(s) for errors and repaired permissions. I've done about all I know to do.<br><br>I used to have these problems occasionally (only on Macs) when I had dialup. But I've never had the problem affect only browsing speed. Actually, since getting DSL I thought the old "sluggish Mac browsing" irritation would be a thing of the past... apparently not. Matter of fact, browsing on the PC and even on the Boot Camp partition on the problematic iMac is faster than browsing on ANY of the Macs. But that's always been the case. (I have no clue what Apple does to slow internet performance down... but it's irritating, to say the least). <br><br>Anyone ever experienced this problem, or have any recommendations? It's just very bizarre that only one Mac on the network is having the problem, and then only browsing the web seems to be affected. I would say it's reasonable to assume the problem is software-related on the one iMac, agree?<br><br>Thanks in advance for any and all opinions/solutions.<br><br>droog <br><br><br><br><br><br><br><br>
Posted by: margadagio

Re: HELP! Sudden, dramatic browsing slowdown! - 09/30/08 05:53 PM

Have you tried dumping all your cookies? I had a problem once like yours and by dumping everything I got back up to speed.<br><br>
Posted by: Nagromme

Re: HELP! Sudden, dramatic browsing slowdown! - 09/30/08 06:22 PM

FWIW, I once had such an issue solved by clearing my web site favicons (an option under Reset Safari). Not sure if Firefox has a similar function--and this was back with Safari 1.<br><br>Is try running YASU--it may fix the problem with little effort.<br><br>nagr[color:red]o</font color=red>mme<br><br>I require stroyent!<br>TeamMacOSX.com | MacClan.net
Posted by: NucleusG4

Re: HELP! Sudden, dramatic browsing slowdown! - 09/30/08 06:38 PM

Funny... I recently started having the same problem on my MBP. I've reset Safari and ran Cocktail... still the same.<br>MP on the same wireless network flies along..<br><br><br><br><br>[image][/image]
Posted by: droogie

Re: HELP! Sudden, dramatic browsing slowdown! - 09/30/08 07:05 PM

Yeah, sorry... I meant to mention I already did that too. Didn't help at all. Also, the longer I browse (during a single session) the worse it gets. Things slow to the point I must close the browser, and sometimes even reboot my computer!<br><br>What good is really fast DSL if.............................. <br><br>Thanks for the guess, Marge! <br><br>droog<br><br>
Posted by: droogie

Re: HELP! Sudden, dramatic browsing slowdown! - 09/30/08 07:10 PM

Funny... I recently started having the same problem on my MBP<br><br>Nothing "funny" about it, damned frustrating... especially when you've tried everything you know to try, huh? This has been going on now for over a week. Wish it would just go away as fast as it surfaced.<br><br>Gotta' go now... I can barely stand waiting for posts/responses to load! <br><br>droog<br><br>
Posted by: iBookmaster

Re: HELP! Sudden, dramatic browsing slowdown! - 09/30/08 07:17 PM

Not sure Droogie. But, have you tried creating a new user to see if you get the slow browsing on that? If you don't, you could copy everything over to the new user and delete your current user. <br><br>Too many lives they've spent across the ocean. Too much money been spent upon the moon. Well, until they make it right, I hope they never sleep at night. They better make some changes and do it soon. -Things Goin' On/Lynyrd Skynyrd
Posted by: Jim_

Re: HELP! Sudden, dramatic browsing slowdown! - 09/30/08 07:56 PM

Have you tried another browser?<br><br>You have given it a reboot, right? Seriously. <br><br>------>#1 - JD's Trivia game<br><br>------>#2 - MM-MCF Trivia game
Posted by: starmillway

Re: HELP! Sudden, dramatic browsing slowdown! - 10/01/08 12:03 AM

Droogie, I had the exact same problem a week or two ago. After talking with Comcast, I removed the Airport Express and rebooted, etc.<br><br>I am only using one Mac for a while and can't use my iPod touch [sad] until I try Reboot's suggestions in my thread here.<br><br>So, try removing your Airport and just surf directly from your cable to see if you get your old surfing speeds. Mine were worse than a dialup before I removed the APX.<br><br><br><br><br>Kate<br><br><br><br><br><br><br><br><P ID="edit"><FONT SIZE=-1><EM>Edited by starmillway on 10/01/08 00:06 AM (server time).</EM></FONT></P>
Posted by: droogie

Re: HELP! Sudden, dramatic browsing slowdown! - 10/01/08 03:14 AM

After talking with Comcast, I removed the Airport Express and rebooted, etc.<br><br>Well, I'm not using Comcast (cable service), but I wouldn't imagine my DSL connect would be that much different. Although, I have heard of things "backing up" with high speed cable connects if conditions are right to do so. <br><br>Are your download speeds as bad as your browsing speeds? Because, remember, my d/l speeds are not affected... ONLY browsing! Weird, huh? <br><br>Nevertheless, I will disconnect and try running straight from my DSL modem... and I'll try resetting/reconfiguring my network. <br><br>I also have a different Airport Base Station than you have.<br><br><br>Mine were worse than a dialup before I removed the APX<br><br>Yeah, mine has actually been worse than dialup a few times. Like I also stated, I actually have to reboot at times. Otherwise, I wouldn't be able to access anything on the web... it just sits there, blank page, progress bar not moving at all. <br><br>Kate, I actually remember this happening a couple of times when I had dialup... but ONLY on my Mac(s). NEVER on my PCs. I've read around and found the Mac OS is famous for this behavior from time to time, regardless of the type of connection. Yet, no one seems to be able to pin down exactly what causes the problem... now, or in the past. I'm starting to believe the "Mac slowdown" posts.<br><br>Anyway, thanks for the help/suggestion, Kate... I will definitely give it a whirl.<br><br>droog<br><br>
Posted by: droogie

Re: HELP! Sudden, dramatic browsing slowdown! - 10/01/08 03:21 AM

Have you tried another browser?<br><br>No... I've tried three different browsers. The exact same problem regardless of browser used. ALL behave the same way. That's why it seems logical to assume this is a Mac OS networking-related problem, or some other software-related issue.<br><br><br> You have given it a reboot, right? Seriously.<br><br>Oh yeah. Matter of fact, I give it a "you" after each thing I try... regardless of a required "reboot" or not.<br><br>Thanks<br><br>droog<br><br>
Posted by: margadagio

Re: HELP! Sudden, dramatic browsing slowdown! - 10/01/08 03:21 AM

Let's recap.<br><br>1) This problem affects only one machine on your network. The other 3 Macs are fine.<br><br>2) ALL browsers display the same slowness.<br><br>Like Reboot said, hope you rebooted. If you haven't done so, I'd do a complete shutdown as well. <br><br>I know this sounds totally off the wall. Is there some app that could be sucking your broadband? I know iChat AV can really slow down browsing speed. Have you used something like Limewire or a Bit Torrent lately? Is there something in your Start Up items that could use broadband?<br><br>Having asked the nonsense above.<br><br>3) You say only browsing is affected. <br><br>I'm stumped.... I'll leave this to the experts. <br><br><br><br><br>
Posted by: droogie

Re: HELP! Sudden, dramatic browsing slowdown! - 10/01/08 03:24 AM

Yeah, at this point I've pretty much tried "all of the above," including your suggestion.<br><br>I'll just keep plugging away at it.<br><br>Thanks Robert <br><br>droog<br><br>
Posted by: Jim_

Re: HELP! Sudden, dramatic browsing slowdown! - 10/01/08 04:36 AM

Maybe you need to flush.<br><br>In Mac OSX Leopard, you can use the command dnscacheutil -flushcache to flush the DNS resolver cache:<br><br>dnscacheutil -flushcache<br>In Mac OSX versions 10.5.1 and before, the command lookupd -flushcache performed the same task:<br><br>lookupd -flushcache<br><br>The cache is usually flushed when you reboot but it's worth a try. Also you said you ran maintenance but try anyway.<br><br>You say you did try another user?<br><br>Can you put a good machine into target disk mode and use it's HD to boot the bad machine to eliminate a hardware issue, but since it gets good download speed, just the lag, probably not, but worth a check.<br><br>------>#1 - JD's Trivia game<br><br>------>#2 - MM-MCF Trivia game
Posted by: margadagio

Re: HELP! Sudden, dramatic browsing slowdown! - 10/01/08 05:10 AM

That's what I was thinking. It's some kind of DNS resolving problem.<br><br>Many folks use OnyX to help with their system maintenance. I've used it with success to flush out all the caches. It does appear to help with system performance.<br><br>It's free so worth a try.<br><br>
Posted by: Nagromme

Re: HELP! Sudden, dramatic browsing slowdown! - 10/01/08 10:05 AM

Sounds like DNS to me too, but one thing I didn't see mentioned here: have you checked Activity Monitor, for either unexpectedly busy processes, or else unexpected net traffic?<br><br>nagr[color:red]o</font color=red>mme<br><br>I require stroyent!<br>TeamMacOSX.com | MacClan.net
Posted by: MacBozo

Re: HELP! Sudden, dramatic browsing slowdown! - 10/01/08 12:08 PM

The irritating pause before downloads commence is also evident when attempting to load web pages<br><br>That sounds like a DNS resolve issue. Have you tried changing IP numbers in the DNS server settings in Network Prefs? Reboot furnished me some that significantly sped things up when I had similar problems. Haven't had a problem since.<br><br>
Posted by: starmillway

Re: HELP! Sudden, dramatic browsing slowdown! - 10/01/08 12:41 PM

Are your download speeds as bad as your browsing speeds? Because, remember, my d/l speeds are not affected... ONLY browsing! Weird, huh? <br><br><br>The exact same thing here with me Droog. I went to my speed measuring sites and got the same high fantastic readings I always do. The DNS problem is probably the culprit. Therefore, I do not believe the brand of APort station matters or even not an Airport as my kids have a Belkin and were experiencing the same thing across town. [Comcast there too] They haven't dealt with their problem at all, as of yet.<br><br>I read several sites with a lot of links so I would just click them all for their own new tab and as they completed loading, then read. Some would time out, being so slow! But I could read the forum that way a lot better. <br><br>I'm still not using the APX as I don't want to screw things up before I get enough time to deal with it all at once.<br><br>Good luck<br><br>Kate<br><br><br>To those who've offered all the other suggestions of things to delete, flush, reset, etc., if I do NOT use APX, but connect directly to the DSL modem, I get normal, speedy surfing [clicking on links]. No need to do all that other stuff -- just not use APX.<br><br>Again, with APX and slow link loading responses, a Speed test produces the same fast upload/download numbers. <br><br>I know I have to get busy and hook up the APX and put in different DNS numbers to either confirm that solution or exclude that as the problem. I will do that. I will do that. Going out to sand and paint now <br><br><br><br><br><P ID="edit"><FONT SIZE=-1><EM>Edited by starmillway on 10/01/08 12:47 PM (server time).</EM></FONT></P>
Posted by: starmillway

Eeeeeeeeeeeeeeeeeeeeeeeeeee! - 10/01/08 12:58 PM

Get a load of this Speed.com test I just did! Fastest I've ever got! 12:52 p.m. PDT<br><br><br><br><br><br><br><br><br>So for historical purposes [I'll need a place to go back to if I screw up things trying to use my APX again], here are shots of sys prefs:<br><br><br><br><br><br><P ID="edit"><FONT SIZE=-1><EM>Edited by starmillway on 10/01/08 01:10 PM (server time).</EM></FONT></P>
Posted by: Jim_

Re: Eeeeeeeeeeeeeeeeeeeeeeeeeee! - 10/01/08 01:51 PM

Remove that 4.2.2.3 from the prefs, then hit Apply before changing the Airport DNS (Domain Name Server) settings. <br><br>Hmm, with 4.2.2.3 in there you shouldn't be having DNS issues at all, Airport or not. Your computer should be looking to that first, if it can't find anything there it then uses the router's DNS, or if you entered nothing in the router (Airport) it will use the default Comcast DNS.<br><br>4.2.2.1 to 4.2.2.6 is Level 3 (used to be Sprint) DNS servers. I think I had you enter that at one time.<br><br>If the DNS doesn't work, try resetting the Airport to factory settings, then set it back up.<br><br>------>#1 - JD's Trivia game<br><br>------>#2 - MM-MCF Trivia game
Posted by: starmillway

Airport X - 10/01/08 03:06 PM

Booted back to Airport X<br><br>In another thread you suggested I use 208.67.222.222 and 208.67.220.220.<br><br>Do I change prefs back to eithernet to enter those numbers instead of the 85.255.113.92 and .80?<br><br><br><br>Another pref panel Airport X shot. Gee whiz, I hate to send this post. It is taking longer than the last slow period I had.<br><br><br><br>I haven't even gone to Airport utility application to do anything. Do I need to?<br><br><br><br><br><br>
Posted by: NucleusG4

Re: HELP! Sudden, dramatic browsing slowdown! - 10/01/08 04:55 PM

OK.. my situation is looking the same.. in a way. I'm having the same issues on my MBP. Using ABX I have slow surfing on the MBP and fast d'loads. On my MP it's fine. <br>My IT guy has remarked twice about my funky DNS numbers when I have the laptop at work. Still not clear on what the issue is. <br>Also, I have had several Airport Utility dialogue boxes when I get home saying that there had been a DNS problem but that it was now resolved. <br>I don't have a clear understanding of how all this works so I can't be more specific or troubleshoot it very well.<br><br><br><br><br>[image][/image]
Posted by: iBookmaster

Re: HELP! Sudden, dramatic browsing slowdown! - 10/01/08 05:10 PM

Well, I'll throw in what I had to do to get my MacBook Pro to work with my router. Brand new out of the box my brand new MacBook Pro saw my network with full bars but wouldn't move/surf. It really threw me. I ended up calling Buffalo (the makers of the router). They told me to take the router off of B/G/N setting and just run it in one single mode like G. I chose G because I have some older Macs that wouldn't work with N. This worked for me. I can't imaging this would fix your problem as you were working great previously but, it's worth a try. <br><br>Too many lives they've spent across the ocean. Too much money been spent upon the moon. Well, until they make it right, I hope they never sleep at night. They better make some changes and do it soon. -Things Goin' On/Lynyrd Skynyrd
Posted by: starmillway

Funky DNS - 10/01/08 06:28 PM

There you go~ Funky DNS<br><br>Spent an hour with the Applecare people. 45 minutes of it doing all the stuff on his list and then he put me on hold while he consulted their Airport Guru.<br><br>Wal-lah! Solution at hand and now I am back to normal.<br><br>Funny thing is, I know exactly when my problems started. Go to this thread and read up on that nasty thing that invaded my url window so that I couldn't type one word in there like CNN and go to CNN.com. I had to type www.cnn.com from that point on.<br><br>I kept getting messages that wanted to send me to antivirusdoc.com site to rid myself of a virus/trojan hors [that THEY] put on my Mac in the first place !!!!!!!!!!!!! <br><br>Apple support rep told me it mucks around with the DNS server and some other things, but that I could do an archive and install of the iMac system. I did just that and am now happily back to normal. No kidding! <br><br>He said there is an application [search Google] that would remove offending stuff, but that archive and install was a more certain way to be sure it is gone.<br><br><br><br><br><br><br>Kate<br><br><br><br><br><br>
Posted by: Swatcat

Re: Funky DNS - 10/01/08 06:36 PM

http://www.dnschanger.com/<br><br>
Posted by: NucleusG4

Re: Funky DNS - 10/01/08 06:39 PM

OK... now it makes sense. I also ran across a couple of sites that gave that malware/whatever and it seemed like that was when it started.<br>But, there has to be a better way to fix than the lengthy reinstall/archive method. What happens if you hit one of those again... tomorrow?<br><br>[image][/image]
Posted by: NucleusG4

The Answer!! - 10/01/08 07:04 PM

At least for me.<br>Kate put the cherry on top for me when she posted what the Aple tech said. I Googled "dns changer removal tool" and found this site/app.... http://www.dnschanger.com/<br><br>From the site...<br>The DNSChanger Trojan Horse, also known as OSX.RSPlug.A and OSX/Puper, has been found on numerous pornographic websites disguising itself as a video codec. Once downloaded and installed, DNSChanger changes the DNS settings on the computer, redirecting websites entered by the user to malicious sites. If personal information is entered on these malicious websites, it can lead to identity theft.<br>At work today my IT guy and I were noticing that the DNS would appear to be correct for moment ... then change right before our eyes.. to some weird DNS numbers. Apparently this Trojan is monitoring and changing the DNS on a moment to moment basis and redirecting your browsing through their site... hence the slowdown in browsing but not in downloading.<br><br>i treid the app and here are some screenies.<br><br>My weird DNS numbers...<br><br><br>The app has detected the DNS changer..<br><br><br><br>Cleared the offender out...<br><br><br>Normal DNS numbers again.. and my speed is normal again.<br><br><br>Well Kate, Droog and meself... I guess we know who the pornos are in here..lol.<br><br><br><br><br><br>[image][/image]
Posted by: starmillway

Re: The Answer!! - 10/01/08 07:28 PM

Well Blabbermouth! Tell the whole world. Go ahead! Destroy my saintly reputation . . .<br><br>Glad you are fixed up good and proper again. What a relief it is. . . <br><br><br><br>Oh yeah, you didn't archive and install! But, you should have seen the dust, cookie crumbs, dead mice, rat droppings, and dirt I got outta my Mac. I'm clean as a whistle! <br><br><br><br><br>
Posted by: Jim_

Re: Funky DNS - 10/01/08 07:36 PM

How I love a happy ending. Thanks for the report, I'm going to add that to my flash drive of utilities I carry. Very interesting. I remember seeing that but forgot. Looks like real world stuff.<br><br>Anyway, what kind of sites do you two hang out at that you both got that? <br><br>------>#1 - JD's Trivia game<br><br>------>#2 - MM-MCF Trivia game
Posted by: Jim_

Re: The Answer!! - 10/01/08 07:37 PM

Glad you got it figured out Nagromme. <br><br><br>------>#1 - JD's Trivia game<br><br>------>#2 - MM-MCF Trivia game
Posted by: starmillway

Re: Funky DNS - 10/01/08 07:48 PM

Garden club and recipe of the day web sites, and of course MM Forums <br><br><br>That was almost 2 months for me. I use to get trojan horses in the old days when I brought PC PageMaker or MS Word document files home from work to modify. As I recall, it was easy to detect them and to get rid of them. But of course I don't remember that now.<br><br><br><br><br><br><br>
Posted by: NucleusG4

Re: The Answer!! - 10/01/08 08:35 PM

OK funny boy... you're just jealous. <br><br>[image][/image]
Posted by: Jim_

Re: The Answer!! - 10/01/08 08:41 PM

Hey, I told you it was DNS though, I get an E for effort.<br><br>------>#1 - JD's Trivia game<br><br>------>#2 - MM-MCF Trivia game
Posted by: starmillway

Re: The Answer!! - 10/01/08 08:50 PM

My hero!<br><br>No lie ... <br><br>tuvm<br><br><br><br><br><br>
Posted by: FSM

Re: The Answer!! - 10/01/08 09:00 PM

whew, that Trojan horse won't affect me then, but thanx for the link so i can pass it on to others. <br><br>--<br>[color:red] Kansas Jayhawks -- 2008 National Champions </font color=red>
Posted by: NucleusG4

Re: The Answer!! - 10/02/08 04:39 AM

Well... I'm pretty sure that Trojan exists on other sites besides porn sites. I posted a link in here one day that was legit... and it redirected everyone to a PC scan for virus site. Lots of people were asking me why I posted that link. It wasn't on purpose... it was a legit link... or so I thought.<br><br>[image][/image]
Posted by: Swatcat

Re: Funky DNS - 10/02/08 01:18 PM

Another way to remove the Trojan is open Library/Internet Plug-ins <br>Look for Quicktime.xpt and trash that file.<br><br>For those who would love to download the Trojan here is a little map to help you out. <br>[color:red]OR JUST STAY AWAY FROM PORN SITES YOU PERVERTS !</font color=red><br><br><br><br><br>
Posted by: Jim_

Re: Funky DNS - 10/02/08 01:31 PM

Thx Swatty. <br><br>------>#1 - JD's Trivia game<br><br>------>#2 - MM-MCF Trivia game
Posted by: droogie

Re: Ok, so... - 10/02/08 04:25 PM

... you got me! The wife will also be thrilled to hear I spend countless hours of my day on my fav porn sites. Considering where the virus was picked up, , it kinda' gives an entirely new level of meaning to the term "Trojan," huh? Hey, how 'bout that "little blonde babe" on the "PleaseDoMe4U.com" site? <br><br>Seriously, I was almost hoping I'd picked up that Trojan so the cure could normalize my browsing once again. However, I downloaded, scanned and there was no Trojan. I'm relieved, but almost disappointed at the same time. <br><br>And I still cannot resolve the issue I'm having... it's maddening at this point. <br><br>Ah well, congrats to you... and please keep both hands on the keyboard when surfing from now on! DOH!<br><br>Thanks for the recommendation just the same! <br><br>droog <br><br>
Posted by: droogie

Re: Kate... - 10/02/08 04:29 PM

... I've tried just about everything at this point... even Nuke's "Trojan" suggestion, but to no avail. I didn't have the Trojan he apparently had. That's not to say I couldn't have something similar I suppose. Although, I don't frequent porn sites, and I have run 4 different anti-virus/spyware applications.<br><br>Ah well, back to the ol' drawing board on this end. <br><br>Kate, thanks for your responsess... it's appreciated greatly. <br><br>droogie<br><br>
Posted by: starmillway

Re: Kate... - 10/02/08 07:02 PM

Sorry bout that Droog. I'm clicking right along faster than a speeding bullet!<br><br>Good luck!<br><br><br>Kate<br><br><br><br><br><br>
Posted by: Jim_

Re: Kate... - 10/02/08 08:36 PM

Have you tried another Ethernet cable, or can you move the machine to a known good connection?<br><br>Do you see anything suspicious in your Console logs? Such as relating to DNS, etc.<br><br>Also you can try the the target disk mode suggestion. Boot your machine from another machine that is in target mode. If it runs fast from that HD you're sure it's not hardware. I doubt it is since actual d/l speeds are good but you never know if the Ethernet chip is getting confused.<br><br>Did you try reinstalling the latest combo update, the big sized one?<br><br>------>#1 - JD's Trivia game<br><br>------>#2 - MM-MCF Trivia game
Posted by: NucleusG4

Re: Kate... - 10/02/08 08:55 PM

Poly already said... Combos are for pussies.<br><br>[image][/image]
Posted by: Jim_

Re: Kate... - 10/02/08 09:24 PM

Well this pus[i][/i]sy has used it more than once to fix anomalies.<br><br>I mean it's poly, right? Consider the source.<br><br>------>#1 - JD's Trivia game<br><br>------>#2 - MM-MCF Trivia game
Posted by: polymerase

Re: did someone say pu[i][/i]ssy ?? ... - 10/03/08 04:50 AM

I'm sitting here with a bit of a slow browser thinking maybe, just maybe, I should go back and do a combo update on the MBA and clear its chakras...<br><br>Naaah, you're still all a bunch of pu[/i]ssies. <br><br>[edit] is the censor becoming smarter? Shi[i]t.<br>
Posted by: MacGizmo

Re: did someone say pu[i][/i]ssy ?? ... - 10/03/08 09:34 AM

The first step to recovery is admitting you have a problem... you're on your way poly! <br><br>
Posted by: MacWoe

Re: HELP! Sudden, dramatic browsing slowdown! - 11/27/08 11:20 AM

I had this same problem.

In my case I found a DNS server entry which I had somehow picked up years ago which stayed active until all of a sudden the long forgotten DNS server as referenced went off line and the DNS queries were suddenly taking ages to resolve.

System Preferences - Network - Advanced. DNS tab. Remove all unwanted DNS entries. Usually there should only be one entry in the list being your NAT router. If you are on a static address then it should be YOUR ISP DNS server not somebody elses.

Just one DNS server in the list which does not respond properly is enough to crawl the browser to become almost unusable.

Hope this helps eliminate at least one possible cause.