Just wanted to share this in case any of our other users run into a similar issue. One of our users was running Now Up-to-Date & Contact 5.3.1 and had no major issues till they began replacing some OS 10.4 machines with 10.5 machines. On the 10.5 machines they could not get Now Up-to-Date & Contact to launch. After exchanging ideas, console logs, and error files, this is what the user did that cleared the problem:

2/20/2008 7:22:28 PM We have lift-off! I'll explain how your developer's comments clued me into how to fix this issue: We are in a corporate environment, using Apple's AD plug-in to authenticate our Macs with our campus Active Directory services. As mentioned, all of machines were running Tiger. That is, until we began to replace machines with new ones that ran Leopard, these two in particular were the first of those. However, machines running 10.5 have had issues with AD, as reported among many of the Mac help sites. One of the early fixes for binding Leopard machines with AD was _disabling_Bonjour_. Which we did via the command line: sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist Hence, the problem we've noted. Since that time, 10.5.2 came out and fixed many issues with AD. All I did here was re-enable Bonjour: sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist I then re-booted and tried NUDT, again. This time, it launched. I've now performed this for both problematic machines and both are now running NUDT--so far, without issue. Thank you for all of your help (and your developer's) with this.
Don Norcross
Technical Support - Now Software Inc