And it is indeed the parentNode that is locked, so the fork. And the default lock is 'FORCE' which is identical to 'UPDATE' (for which 'pessimistic' in jbpm is a synonym. UPGRADE_NOWAIT is another oracle specific one, just not sure (and no time to find out) what the exact difference is. Btw, could you try to make the transition to the tasknode the first one? It is not realy deterministic, the order in which they are processed, but I'm curious if it makes a difference at all if one of the transitions has gone to a persistent node before the others are processed. The order is my best guess to be able to achieve this View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4196596#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...