*cbeer*
>If the transaction shared the same underlying session, I wonder if that's enough to declare it equal? Certainly changing one will 
>change the other..
*Adam*
>Yes, it certainly is.

But the Transaction could still have different e.g. expiry dates. A user depending on these might throw away a Transaction object with a later expiry date, because he already has a reference to an "equal" one, with earlier expiry date.