They are, in essence, single threaded for the signal being executed but it sounds as if there is a bug somewhere.
What type of error are you seeing?
My guess would be that the unlock of the token has been rolled back by the transaction and the token will therefore need to be explicitly unlocked before it can be used.
Can you create a JIRA for this and attach an example of the failure?
Yes, I had a quick look into it. I call an EJB which must join the transaction, this EJB then throws a RuntimeException which would then rollback. I will create a Jira.
Great, thanks very much.