Arkona has a feature for GM only that changes the cost of a part when the RO is warranty and a purchase order is written to pick up the part locally. When this happens it causes the auto claim download to GM to fail as there are no part numbers associated with these lines on the invoice. The warranty invoice will show "cost difference" with money next to it.
Doug Heisel at Arkona told me there is no way to turn off this function. Has anyone found a way around this problem.