I could see is UnifiedLoaderRepository3 indeed sends a notificaton of the classLoader... and if you buffer such notification that would generate a leak. http://anonsvn.jboss.org/repos/jbossas/branches/Branch_4_2/jmx/src/main/o... I don't know how to avoid the buffer on the sun's implementation. One thing that I thought though, was to make the attribute source on javax.management.Notification a WeakReference, but sounds a weird solution. (Brain storm). http://anonsvn.jboss.org/repos/jbossas/branches/Branch_4_2/jmx/src/main/j... Another possibility would be to not send ClassLoading notifications when using Sun's JMX? (Another brain storm) This is a job for JMX/ClassLoader experts. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4075251#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...