Default values "PO Price" not able to set in PR While MRP

Hi,

I have maintained the item defaults values for PR in ME51N transaction as - PO Price - 1- As Gross Price and checked the box always propose

Now When I am creating the PR manually systems works fine and I can see the default value in  'PO Price'   as 1- As Gross Price*

But when I am generating the PR through MRP through my ID only this defaults values for PR in ME51N transaction as - PO Price - 1- As Gross Price is not workng and system putting the value as  Do not adopt. in PO price field.

*So Can any body tell me how to default value of  1- As Gross Price  in  'PO Price' field in Purchase req. in valuation tab.*

sapaman man