Entering a chatroom with many participants burns your cpu
Try to enter this chatroom:
debian-devel%irc.debian.org@irc.jabber.cd.chalmers.se
It is usually pretty crowd, and on my 2ghz amd64 it takes like 10 seconds of complete CPU usage to fill in the participants list. I agree that jabber conference rooms are usually not so crowd, and thus it not worth spending time optimizing this operation, but here it really seems there is a bad piece of code since performances are incredibly bad.
Cheers