You are attempting to use a non XA resource
in transaction with an XA resource.
Non XA doesn't have two phase commit.
The non XA commit could fail (one phase) while the other
resources are committed.
Probably not what you want, hence the warning.
You probably need to use the XAConnectionFactory (look under $JBOSS_HOME/docs) for your database connection, not the usual LocalConnectionFactory. You may also consider just using the NoTxConnectionFactory, which doesn't have 2-phase commit, but hides those warnings.