"rtm333" wrote : Hi Tim, | | Thanks for your quick reply. | | The first problem, namely the failure to receive any JMS messages and the subsequent timeout exceptions on the server, does not occur when the explicit ip address is specified. In this case, the special client behaves just like any other "normal" client. | | I can't be sure whether the server lock-up is really related to this client. Probably yes, as up to now, we have observed the lock-up only when this peculiar client has attempted to connect (without providing the explicit ip address) several times. | Makes sense from what I saw in the code... We are synchronizing sessions hashmap... while the server is also closing the tree.. and on that process we are flushing messages to the client... Because we can't reach the client... we are holding the HashMap locked on setStarted. I will try to create a testcase based in what you said. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4016436#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...