Muhammad,
Those FI document postings look strange to me, too. The two letter codes seem to be special ledgers, and I don't see those sorts of entries in my system when I do a GR for an account assigned PO.
I don't have many more ideas, except checking to see if you've assigned the purchasing organization to a company code and the plant used by your PO item to a company code. Do you see a value of the GR in the PO history tab?
- Jeff