It's not that there is any XA or non-XA queue, but the connection factory and associated session is XA or non-XA.
thanks a lot for the clarification!
After some further research, I stumbled over http://www.odi.ch/weblog/posting.php?posting=210
Your hint and that document in conjunction with http://wiki.jboss.org/wiki/Wiki.jsp?page=ConfigJBossMQDB solved my problem.
Now, it seems to be working the way I want it. I'm still doing some tests, but it looks already pretty good.
Best regards, Marco :-)