Hi Jaikiran,
Thanks for the response. I take your point that we are running on an old implementation of ejb3. However, we have been for some time without any issues, so we found it strange that we are all of a sudden getting deadlocks in our application. We attempted to move over to jboss 5.1 some time ago, but we encountered some issues which forced us to move back to 4.2.3.
We will look at the change logs to see if there are any relevant bug fixes/upgrades that pertain to this issue.