Judging by this thread posted in the JBossMQ forum,http://www.jboss.com/index.html?module=bb&op=viewtopic&t=119574you've got a bug in JBoss Messaging:See JMS Spec 3.8.1.3Wrong
DeliveryMode = 2
DeliveryMode = 'PERSISTENT'
Thxhttp://jira.jboss.com/jira/browse/JBMESSAGING-1091