I'm not sure what's happening, but it looks like you have a classLoader issue. Probably you have another version of JBossRemoting in your client. Make sure you are using jboss-messaging-client.jar in your client, and you don't have any other jboss-remoting.jar version there. Another small possibility would be your network configuration / callback configuration. Take a look at the manual for more information on callbacks: http://labs.jboss.com/file-access/default/members/jbossmessaging/freezone... View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3987913#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...