I've investigated a little bit and it appears as if the session that it complains about is created on the other end. That is, the SessionDelegate is registered with ServerPeer on the "messaging2" end but the lookup happens on the "messaging" end where the session is not known, causing the IllegalStateException to be thrown. Is it possible that there's a bug in the way sessions are created in Bridge.java in the case (qualityOfServiceMode == QOS_ONCE_AND_ONLY_ONCE && !sourceAndTargetSameServer) ? Could lines 930-932 / 1013-1015 in Bridge.java in TRUNK be the culprit? I can't really wrap my head around sessions and transaction handling in the bridge, but is it possible that the sourceSession has to be (counter-intuitively) created from the targetConnection in this case? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4087479#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...