Many ICQ users woke up and found their ICQ numbers were no longer working. There is a topic on the ICQ support with more than 1,500 replies. There are pages upon pages of other topics asking what happened. As of yet, there has been no official response from AOL about what has happened. But don't panic. It appears to just be a bug, and your numbers are safe. Backup, remove, reinstall as described here.

If you use ICQ6 and your account becomes locked -- and you even cannot retrieve password or reset via web, UNINSTALL the ICQ6 client and reinstall. Remove all user data!

This has happened to me and a friend already. Very frustrating. I use it at work and home. It did not work anywhere.

This is a nasty ICQ6 bug, but it is fixed with a complete uninstall of all user data and reinstall.