I respectfully disagree. I just ran another case where I created an order on the store-side, then went to edit orders. I added a product with a quantity discount in edit orders. The subtotal, discount, shipping, and tax were correct, but the order total was too low by $0.06. Then I clicked update, got a successful update message, and the subtotal, discount, shipping, and tax were the same and correct, but the order total was too low by the tax on the discount, exactly the same behavior that I saw when editing an order started in Admin New Order. I think there's a problem with Quantity Discount or a problem in Edit Orders with discounts. I plan to run further tests. Sorry for being a PIA on this problem.