If it were me, I'd review the database setup guide to make sure that the correct tables were created, and the permissions are assigned properly for the user configured in IMP.
It may be possible to review logging from the text conferencing service to see if it contains SQL errors or some other information that can help narrow down the fault.
From what I glean, it's not a particularly complicated item, it simply reads what is present when it loads then keeps track of changes as it shuttles back and forth between the IMP server and the database. Jabber is a pretty dumb client and only really responds to messages it receives from the server, and doesn't do much of anything client side.
