mskonda, I'm not sure whether the current discussion is still related to my original problem(s). In fact, we had two issues with SP2 that I described in this thread: 1) "IOException: Mismatch version of JBossSerialization signature" was thrown occasionally on the server side, although it worked most of the time without problems. 2) When an ExceptionListener was set on the client side, a new TCP connection was opened every two seconds by the ConnectionValidator. I have not observed either issue since upgrading to JBM 1.0.1.SP4. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4031386#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...