I'm sorry to cause such a fuss but if you say that this is how QB was designed then I have to question the design and ask that this be fixed as a design flaw (or bug) instead of a software bug. In the scenario I described, the customer is billed when an invoice is created from the Sales Order and NOT from the "billable" route. An item should not default to "billable" just because you have created a PO from a Sales Order or because you assign a customer to an item in a PO. Also, there is supposed to be a preference item that allows you to turn off the "billable" default option but it does not work.
