Supplier Location Question

I have a question for anyone using Peoplesoft eProcurement.  If you have a supplier that has multiple ordering locations that you may order the same item from, do you have to setup each of the price locations at the item supplier purchasing UOMs screen?  We are currently on 9.2 and are finding that if we don’t setup both price locations at the supplier UOM, we receive sourcing errors.  We are trying to standardize our item setup and we are wondering if the extra price location is necessary.  We have tried associating the same price location to all of our suppliers