VALUATION TYPE AND STORAGE LOCATION

When trying to do a Good Receipt on a subcontract PO against a line item with non-valuated material (UNBW) and Account Assignment "K" (cost center), the system is asking for a Storage Location and is putting the non-valuated material into stock. We are using the UNBW material and the Acct Assginment K PO Line Item as a cost collector for services performed against a supplier. The UNBW material should NOT go into inventory.

CAN SOME ONE TELL ME IF THIS IS STANDARD SAP OR SOME CONFIG THAT IS MAKING THE NON-VALUATED MATERIAL SUBJECT TO STOCK

THANK YOU IN ADVANCE