I use Trillian Version 2.01 Pro, and have had no problems.
It does not disconnect/reconnect etc like the stand alone ICQ does at the moment.
(The Pro version is less 'buggy' than the free version, save & except for the small inconvienance of it contacting everyone on your icq list for authorisation the first time you install it - however this *could* be seen as a feature ie you get to talk to peps you may not have touched base with in a while 
)