After scrounging around the forums myself about this topic yesterday I found a method that works (but with a caveat). The JMS spec, apparantly, does not require that the message be delivered sequentially. Why? I dunno, particularly for a Queue (unless I miss read previous posts and this is only applicable to publish subscribe).
Anyway, here's my jboss.xml for the MDB test that I did that worked for me, it basically defines a specific configuration for that bean:
<container-configuration extends="Standard Message Driven Bean">