The driver version is probably too old (or too new) since jBPM has been verified to work with MySQL. The DBMS and driver versions tested are listed in http://www.jboss.org/community/wiki/jBPM3PlatformSupport That said, you are better off using the non-XA data source. MySQL (as of 5.0.27) does not actually support 2PC and the XA data source is just an adapter for the interface that does not implement recovery. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4243070#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...