"adrian(a)jboss.org" wrote : I think I know what the problem is, but if I'm correct it will be very difficult to reproduce the problem. | The reason I think it will be difficult to reproduce the problem is because I think this only occurs when you hit the ClassCircularity bug. The releaseInNextTask == true means that it got a temporary lock on the classloader. Its not the original classloader used to initiate the classloading attempt. This can only occur if the thread owns the classloader so it should in normal circumstances be able to complete the task, release the classloader and reschedule back the other requests. If however, it hits the ClassCircularity problem (see the catch block just above the unlock), it will reschedule that task. So when it does the unlock, it will loop on the reassignment of the task back to the same thread. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4206700#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...