For a new RM we call start and then add it to the list of participants. OK if there are no errors, but xa_start could throw an exception. Although we catch that exception and rollback the tx, the resource in question has not been added to the list of participants so doesn't get the resultant xa_end/xa_rollback invocation. The addition of the entry to the participant list should be in a finally block within TransactionImple. (Check JTS too.)