Next time you cannot login, edit the ICQ server list (here is a list of servers:
http://www.arcwebserv.com/jumpsite/icq.html).
Or you can download Trillian-- I've never ever had a problem connecting to a server with Trillian (
www.trillian.cc).
If I had a penny for everytime someone posted about not being able to connect to ICQ, I'd have enough money to buy The Hun and redirect it to Google.