Hi Thom, I've found that we had a leak with some QueueConnection / QueueSession in CLIENT_ACKNOWLEDGE mode : some messages where retrieved but not acknowledged. (Symptom : ClientCount in DestinationManager is always growing). Thoses messages were consumed from an another session. I guess that this leak generated some ressource shortage for JMS and explains the provider failure. François View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3999779#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...