Pricing Procedure of STO PO

Hi SAP Gurus,

In case of Intra company STO with delivery,there is no condition tab.in PO.In SAP the pricing procedure of STO is RM2000 where the condition type is

P101.So it will applicable for Intra Comany STO with delivery or Only in Inter Company STO(two C.Code).In case Inter Company STO we treat Supplying plant as Vendor so default pricing procedure it can get RM0000.I want to know in case of Inter company and Intra company STO which pricing procedure will be used?In which cases P101 condition type will be used?

In Case of Inter company STO PO i tried by making assignment of schema group POrg,Doc type(NB),Supplying Plant,Procedure(RM2000)

In PO condition type P101 coming but net price is not calculated it showing message "Error in net price calculation..net price is negative"

I am Puzzle.So please give suggestion regarding pricing procedure of Different type of STO.