When I try to go online through Miranda I receive an error "You were rejected by server for unknown reason. This can happen if the UIN is already connected." But when I try to connect through ICQ 5 all works fine.
Before that I used another Miranda client (other build version) and when it stopped working (because of that error) I installed other build version of Miranda and all worked until today...

What the hell?

did you read this ?
http://forums.miranda-im.org/showthread.ph...light=ICQ+fatal

Thank you! Looks like the problem is in protocol.