Tim, as I said at the outset, this is not necessarily a JBoss Messaging issue. However, that said, the use of AOP with or independently of the JBoss AS (4.2.0.GA BTW) should not break the implementation of messaging since the jar in question is provided externally to Red Hat (Doug Lea's concurrency utilities) Since JBoss AS (4.2.X) is using this version of AOP anyway, why should the jar's be different. Also, there have been many conversations of the evils of using jbossall-client.jar if you would care to search the lists for them. It has been repeatedly recommended that explicit collection of client jars required be used for deployment. This allows significantly more flexibility when moving part of the container to newer versions. This is more of a request to the AOP team to get the concurrent.jar in line with everything else. Regards, Karl View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4058887#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...