If this only occurs after long periods of inactivity, possibly your connections are timing out. I would expect an exception to appear due to the broken connection... but you might try setting idle timeout up. I can't remember all the nonsense you have to go throught in pre -3 jboss to do this... I think you need IdleTimeoutEnabled=true, GCEnabled=true, IdleTimeoutMillis=(30 min in millis), GCIntervalMillis=(maybe 10 min in millis). That might be enough...
Thanks -- I'll look into this some more.
I noticed over the weekend that the beans I am having a problem with are the only ones I haven't defined in jaws.xml (there was no need). This resulted in JBoss attempting to create existing tables:
[JAWS] java.sql.SQLException: ORA-00955: name is already used by an existing object
This is likely because JBoss is doing a case-sensitive search for tables to see if they exist, and not finding them in Oracle.
I'm hoping this will put an end to the original problem I posted.