MRP issue for future delivery PO/STO date

We have a sceanrio where the available material quantity in MRP list is considering future delivery date STO quantity. The PO delivery date is 08.11.2008 and MRP run date is 07.11.2008.

Step 1, material master details:

Material = 16814, MRP Type = PD, Lot size = EX, Special Procurement = D0 (Stock Transfer), Consumption mode = 2 Backward\forward consumption, Fwd Consumption per = 0.

Step 2, MRP list details , before PO creation:

MRP list before having any purchase order = 191-

i.e, Available qty on 07.11.2008 with a DepReq = 191-

Step 3, Creating Purchase oder (In our case it is STO):

We created one Stock Transport Order on 7th Nov 2008 giving Delivery date as 08 Nov 2008 which is in future. Our plant is receiving plant = y100.

PO quantity = 2

Step 4, Running MRP in MD02:

Processing key = NETCH Net Change in Total Horizon

Create purchase req. = 1 Purchase requisitions

Delivery schedules = 3 Schedule lines

Create MRP list = 1 MRP list

Planning mode = 3 Delete and recreate planning data

Scheduling = 1 Determination of Basic Dates for Pl

Result = PR is getting created for Qty = 189, but our actual required qty = 191 - meaning it is considering the future delivery date(8th Nov 2008) PO qty while creating PR and removing that qty while creating PR's on 7th Nov 2008.

Here we are running the MRP on today (7th Nov 2008). STO delivery date is 8th Nov 2008

Step 5, MRP List details, after STO creation:

Now the PO is coming in MRP list and the available qty is 189-

Earlier stock before purchase order is 191 - after creating purchase order (STO) for future delivery date available qty is coming as 189-

DepReq is still 191- but the total available qty is changing to 189-

We want PR to be created for DepReq of 191 and not 189.