This is strange. AFAICT, the NPE should only happen if the Client.invoke call returns null, which should not happen. At first I thought your problem might be an artifact of http://jira.jboss.com/jira/browse/JBAS-4815, but that's a problem when multiple threads share the same bean proxy. Your code doesn't work that way; they share the home proxy but not the bean proxy. Do you have a test case that can reproduce this? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4124145#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...