Well, you are using transactions even if you don't know it - every database query is executed in a transaction, even simple select queries. Seam and Hibernate are by default configured to make transactions
just workwithout users having to worry about transaction demarcation for most purposes.
It seems like your problem is not unknown - if the solutions you can find in the web don't help, you might want to check in the Hibernate forums, since the exception is thrown in Hibernate code.
Yep I probably will post it on HForums also , but I was thinking that seam is managing all the session stuff
maybe it is connected somehow. It seams like the connection is being messed up between the sessions.