A quick note for anyone who upgraded to iPhone OS 3.1 recently. Upon upgrading and syncing, iTunes told me that my computer was no longer authorized to use the iPhone apps I downloaded, and if I did not authorize the computer immediately, all of my apps would be deleted. What could I do? I authorized, of course, but only to have iTunes 9 tell me that I now have 2 computers authorized out of the allowed 5 (instead of just 1, like it’s always been).
If anyone else has this issue, here’s the quick fix. In iTunes, go to the Store menu item, click it, then click on Deauthorize Computer. Enter your password to deauthorize the machine. Then do it again. That’s right – deauthorize your computer a second time. Then go back to the Store menu item in iTunes, and click Authorize Computer. Enter your password to authorize your computer, and voila, the count is back to normal. At least, that’s how it worked out for me. Good luck!