JBoss-6.1.0-SNAPSHOT - Adding @WebService causes EJBException "Named query not found"

We faced an issue when a webservice annotation is added to a session bean and there are two persistence units defined. All of them are in the same ejb module defined and packed in an ear. The behaviour is not predictable, some times it works but most of the times, not. Without the @Webservice annotation, we don't have deployment issues.