Have you migrated the same transaction isolation level settings from SUN APP to JBossAS?
This looks like a duplicate of this other thread https://community.jboss.org/message/827000#827000. I'll close the other one and let this thread stay since the Bruno has a bit more details about the application here, than he does in that other thread.
Yes, we migrated the same transaction isolation which is TRANSACTION_READ_COMMITTED.
However, I found out that, In jboss, we are using datasource while in SUN App we are using XADataSource.
would this have a factor?