I have a Purchase Order with this data:
Purchase Date: 05-01-05
Currency: DLL (US Dollars)
Rate: 11.3805 (home currency is MXP)
Qty Approved: 27796 Kg
Purchase Price: 0.7234

So the total of the qty received is: 20,107.62 DLL

Then we made a batch with the entry date of 05-01-05 in this date the currency rate is 11.3805 MXP per DLL

The supplier sends us two invoices for this receipt:
First one for:
Date: 05-01-05
Qty: 9262 kg
Currency: DLL
Rate: 11.3805
Price: 0.7234
Amount: 6700.13 DLL

So we match partially the reception for 9262 kg and 6700.13 at this time its ok.

But for the second invoice we create a batch with the entry date of 31-01-05 the currency rate for this date is 11.2613

For this second invoice we entry as document date 05-01-05 and the currency rate 11.3805. We don’t have price difference, currency diff. (by document date)
Date :05-01-05
Qty: 18534 kg (rest of the reception)
Currency: DLL
Rate:11.3805 (document rate)
Price: 0.7234
Amount: 13407.49

When the system display the session for match tfacp1131s000, the receipt of the PO displays:
Qty Amount
Partially 9262 6629.84 (instead of 6700.13)

If we zoom to the session tfacp1132s000 it show the first invoice with the correct amount (6700.13 DLL) The diff. Is because the system take the currency rate of the batch date
6700*11.2613=75452.17 MXP
6700*11.3807=76252.16 MXP
75452.17-76252.16 = 799.99/11.3807 = 70.29
6700.13-6629.84= 70.29

Why the system calculates in this field (match amount) a currency dif. If the invoice and p.order have the same currency?
And why takes the rates of the entry date at batch header instead of the currency rate of the document?

Is this a bug?

Regards