It looks like an EJB3 error.
But I would take a look if you're not leaking resources. (Like, if you use BMT.. make sure you are properly managing transactions, and closing sessions.. etc)
You should ask about that exception on the EJB3 forum... but take a look at any programming errors like that before asking them.
I would also try HornetQ Beta5 as there have been a few fixes in the JCA layer between the 2 versions.