Glad it worked. I can only speculate on the MDB undeploy behavior; for a better answer you'd probably need to post on EJB or JMS forums. :) Pure speculation: As you undeploy it's in the stop() method for the container. Sees there are active beans so the deployer thread blocks waiting for that to clear. It happens that stop() is coded in such a way that the blocking occurs before the step gets executed that prevents creating new MDB instances to handle the new messages you generate. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4105645#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...