Can somebody tell me how do I mention the application isolation in JBoss4.2.2 Messaging instance?

I have tried doing the following in Jboss-service.xml which is packed part of the sar file.

<loader-repository>istay.classloader:loader=CoreServices_istay2.ear</loader-repository>

During deploying, JBoss prompt a message saying only root level config can mention the loader respository hence ingnoring the setting done.

My need is to deply two ear of same application pointing to two different queues.Application deployment goes fine but my client request is processed by the ear which is not suppose to do. How do I handle this class loader issue?