Interesting, I was going to ask a similar question. When I authorized my new notebook for ITunes, it was the 5th and final one. At least one of the computers that had been authorized for my iTunes account is dead as well.
So if I contact Support, I wonder if that counts as my one and only free call for the new computer. If so, I'll nose around to find the place to deauthorize everything, and then, as yoyo suggested, reauthorize them, one by one.
This brings up another question. I tried to load an album that I'd downloaded from iTunes to the new comptuer. I have gotten the firewire or ethernet cords yet to do a transfer, so I just used the disk I made of the downloaded album. I got a message that I didn't have the authorization to listen to the album on this computer. What gives?
Thanks once more,