Subcontracting multiple BoM levels for Project Stock

Hi,

We are an engineer / make-to-order manufacturer, so we use a lot of "individual" type materials (instead of collective).  We are trying to subcontract several BoM levels of work to different vendors, and we are seeing many false requirements.

So we have something like this (this is all in project / wbs element stock):

1. Make here
   1. Subcontract Requisition
      1. Make here
         1. Raw material
      2. Subcontract Purchase Order
         1. Make here
            1. Raw material
            2. Raw material
      3. Make here
         1. Raw material

The subcontracting items are driving additional false MRP requirements (planned orders and purchase requisitions) for all the raw materials under them.

I figured out how to fix the subcontract on level 3 by transferring the HALB material from project stock to unrestricted stock (411Q), then transferring it to subcontract stock (541) (Is there a better way to do this?  Now I can't see my project-specific stock line for that item).  But, while that purchase order is still open, there's nothing I can transfer to make the extra, false requirements disappear.  Also, I am getting an MRP exception telling me to cancel the PO because it doesn't see the dependent requirement for the subcontract requisition above it.

Does this question make sense?  How can we fix it?  I need to get that subcontract requisition to see that its material will come from the subcontract purchase order.

Thanks!

Timothy