I do not see that happening (b58g, oracle) with your use-case (only jdbc, no other resource involved).
Are you able to see the issue in the transaction without connector resource ?
Could you please post your ejb source, deployment descriptors and connection pool configuration ?
Thanks,
-Jagadish
[Message sent by forum member 'jr158900' (jr158900)]
http://forums.java.net/jive/thread.jspa?messageID=249070