>>EJB invocations wouldnt really create daemon threads, would they...
I don't know (which is why I said "almost as if"), I'm not sure under which circumstances a thread gets marked as daemon and I'm too busy to try some experiments to find out. But the idea is probably correct - something new got started and that caused the threads to be created. Initially I thought opening a database connection, but I don't think that each connection gets its own thread. But it has to be something.