Change the procedures used to update inventory on "LB." items. Normally when an "LB." item is sold, but no weight information has been provided, the "On Hand Weight" value of the item is not altered (although the "Quantity Ordered" amount is added to Allocations).
This modification also changes the process so that the "Quantity Ordered" amount is also deducted from "On Hand". When actual weight information is provided then the "On Hand" value is adjusted based on the difference between "Quantity Ordered" and the actual shipped weight.