I added custom fields from SINVOICE and SINVOICEV to the Open Items left list for payment entry (DU6).  I added the SINVOICE and SINVOICEV tables to the environment tab, and linked them to the GACCDUDATE record.  I validated the DU6 object, and the payment entry transactions.  The columns appear, but they are not being populated with data.  Does anybody know if there is another step I need to do to make sure the values get populated?