So to finally help myself I downloaded the source for JBoss 3.2.5 and am tracing through it. It appears that the exception is thrown on the invocation of the findByUserName method in the TxManager class. I have not been able to trace further, but it bring to my attention how there can never be a dearth of documentation. And open source is just a poor step above closed source in the absence of good documentation. :-) Enough said lest I induce myself to start documenting the JBoss code :-) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3983372#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...