a value of 5 here for QtyShrtOpt does not cause a error to kick back as expected (as my great plains partner told me it would), in reality it only shifted the qty to the "Qty Canceled" field in the transaction rather than the qty billed field. This resulted in a extended price on the line of 0, which means the document amount was 0, causing a error of discount can not exceed document amount, cause the discount was set as if the qty was being billed.
hope that makes sense to you. Anyway, I am now going to try unchecking "Allow Backorders" in setup, and change the QtyShrtOpt value to 3, meaning backorder all in the case of a shortage, my hopes are that trying to backorder when it isnt allowed will cause the error to come back like I want, therefore keeping the invoice from integrating, meaning it will remain in the shipping system.
I will let ya know after I try it how this approach works.
Doug