Ah, more information - you are using
EJB 2.x with Container Managed Persistence (CMP), is that correct? In that case,
you should not use use commit option A, you should use commit options B or C. As I pointed out, accessing a single database from multiple applications (multiple instances of JBoss AS in this case) works only if those applications do not assume exclusive access to the database.
Thank you for the nice comments about the book.