hi guys,
if you are using ICQ or any alternate ICQ client and having problems with the logon since yesterday, so this happens because ICQ has changed the login stuff on the 28.05.2008! Since this time its only possible to login with the MD5 checksum.
If you are using the original ICQ client, you may have problems with this when using a version < ICQ6... Just use ICQ6+! When using any alternate ICQ client (most open source projects) and having problems to login, you have to change and activate the option "safe Login" (german: sicheren login) and the login should work again! Good luck hope this may help some guys... best regards
[Edited]
When using the great opensource mutli-client "pidgin", you have to go to your ICQ account window -> Edit (bearbeiten) -> Go to the "Advanced" (erweitert) Tab -> and activate the checkbox "using AIM/ICQ proxyserver".... good luck
[Edited]
Source of information:
http://de.wikipedia.org/wiki/ICQ