Did you check to see if the Ship Invoice Complete box was checked.

That doesn't help. I'm thinking this has to be a bug. The Ship Invoice Complete check box does the same thing as the result of answering the "Do you want to ship the complete sales order?" prompt when selecting the Lines panel after entering a number in the "Sales Order Number" field during invoice creation. It either, sets the Quantity Shipped to the Quantity Ordered for all lines or sets them all to zero. It selects all sales order lines if only one PromiseDate is matched with or without that checked.

That doesn't help. I'm thinking this has to be a bug. The Ship Invoice Complete check box does the same thing as the result of answering the "Do you want to ship the complete sales order?" prompt when selecting the Lines panel after entering a number in the "Sales Order Number" field during invoice creation. It either, sets the Quantity Shipped to the Quantity Ordered for all lines or sets them all to zero. It selects all sales order lines if only one PromiseDate is matched with or without that checked.