Apologies for the higher-than-average PartyChat flakiness recently, we've hopefully fixed the problem, so things should be stabler moving forward.
The problem, for those who are curious, is that PartyChat uses the Smack library to connect to Google Talk. Google Talk was sending us delayed information (e.g. offline chat) information with poorly formatted time stamps (e.g. "200753T17:56:30") which would cause the connection to die. My friend, and new PartyChat addict, Neil upgraded us to the newest version of Smack in a hurry and turned off the delayed message parser which, for now, seems to have solved the problem.
You also may have stumbled upon a number of unannounced new commands in PartyChat recently -- I hope to post an update explaining how to use these features in detail soon.