I think eventually jBPM should be able to cope with this situation and return a more batural error like "task already taken by ...." View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4265668#4265668 Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=4265668