Olivier, please can you post the part of the stack trace that comes before this? At the start of the trace above, the transaction is already active, but we don't know what has previously been done with it. I suspect hibernate has enlisted a LastResource into it earlier and is trying to do so again, which will cause problems in the version you are running. You could also try grabbing the .jars for the latest stable build from http://repository.jboss.com/jboss/jbossts14/4.2.3.CR4/lib/ and installing them over the top of the existing ones. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4030587#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...