Hi David,
I believe the answer is that prior to AS 4.2, 0.0.0.0 was interpreted to mean "all addresses", but, for the sake of security, it is interpreted as "127.0.0.1" as of AS 4.2. You could inquire on the EJB3 users forum for verification: http://community.jboss.org/en/ejb3?view=discussions.
-Ron