Green man? http://www.spiritandflesh.com/Green-man.gif :) (it is late here, forgive me hehe).
XA datasource is a datasource that can be managed by the transaction manager. As jbpm5 uses JPA transactions, you need to use a data source that supports xa interfaces (xadatasource, xaconnection, etc).
You can try with the configuration I posted in the last message.
Demian
