I believe the example login module configuration in this file is incorrect, at least it caused me a lot of problems before I changed it.
I changed:
<module-option name = "managedConnectionFactoryName">jboss.jca:service=LocalTxDS,name=MSSQLDS</module-option>
to:
<module-option name = "managedConnectionFactoryName">jboss.jca:service=LocalTxCM,name=MSSQLDS</module-option>
Thanks!
fixed in cvs