We only set the context classloader in one place and this is nowhere near any message delivery code. We also unset is immediately afterwards in a finally, so I doubt it is the cause of your problem. Earlier versions of JBM did set the context classloader in other places - what version are you using? FWIW - I can see code in JBAS 4.2 (org.jboss.ejb.plugins.jms.JMSContainerInvoker::invoke) that sets the context classloader. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4069411#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...