For people who reflexively press on the "OK" button whenever there's a new update available, now is a good time to practice restraint. Disgruntled iTunes users have updated to iTunes 7.3 - the new update required for iPhone users - and found themselves getting the message "unknown error - 50" which prevents them from saving any changes to the library after the update.

Some people uninstalled their iTunes to remedy the problem (Note: Remember to backup your files before doing so) and rolled back to iTunes 7.2. Many iTunes users - most of them not owning or not even planning to own an iPhone - were very disappointed with the bugged update so far, to say the least.

If you happen to get the same problem, it's best to call Apple's support hotline to get proper assistance.