Unfortunately this is where were having a problem, we have been unable to replicate this issue. We have tried putting a testing cluster behind the same subnet (obiviously only changing partitions,multicast ips and ports) and passed through 5 million messages successfully. This took between 1-2 days due to messaging processing time of our application. However, our application probably only processed in the region of 7-800k messages inbetween this issue happening. We used the same zip of jboss ( messaging installed, config etc) we use on our production system. I suppose the next step would be to turn prefetchSize to 1000 to try rule out jira issue 1245 View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4135583#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...