If you enter a room that requires authorizing and the app closes for whatever reason, it then becomes impossible to open the app back up and continue because you automatically get banned from that group before you can re-auth your account. After getting the message saying I was banned, the app is then frozen, requiring you to close the app again and start over. But then you get banned again.
ElizaKay about Colloquy - IRC Client, v1.8.2