This could possibly be the omission of the From field sent by clients XMPP during the Bind request some clients like Trillian do this. We have fixed this issue and the Bind requests get processed correctly now. The next minor release will have a fix for this.
I'm not sure if this is the issue here but if you can let us know the client we can test it out.
Matt Petty
Senior Software Developer
SmarterTools Inc.
www.smartertools.com