When using the same connection in multiple threads, we may end-up with a connection returned in the XA pool with the wrong state.
ie:
2013-09-06 16:56:03,264 WARN (Nuxeo Async Events 1-4) [Transaction] Unable to enlist XAResource org.apache.geronimo.transaction.manager.WrapperNamedXAResource@be5bd3, errorCode: -6
javax.transaction.xa.XAException: Already started
One way of reproducing is to break in a seam request thread and invoke the log-out action.