When the JBossMQ node fails with messages currently being delivered to the clients,
the redelivery status is not updated after the node is recovered (either locally or on a different for HAJMS).
The issue is that the redelivery status (in the database) is not updated until the server receives the NACK
(which it won't do if it has crashed).
A potential fix, is to update the status early before delivering the message to the client,
see the forum thread for more detail.