Sorry to bounce this back to the top, but I;m having the same problem.
Just installed Jboss3rc1 and when running code which ran fine on Jboss2.4.4 it now produces a nullpointer exception when run on JBoss3rc1.
The problem occurs:
TopicConnectionFactory topCon = (TopicConnectionFactory)m_context.lookup(m_topicConnectionFactoryName);
No namingexceptions, no other exceptions. But the returned TopicConnectionFactory is null, anybody any clues of why that is?