PO Quantity changed after GR an IR posted.

Hi Gurus,

1) In some cases end user can change PO quantity even after GR and IR done for full quantity mentioned in PO.

Client made a PO with quantity 5 EA .

GR and IR for all these all 5 items were done on 3-11-2008.

But PO now showing quantity 150 Ea in PO..

So I check changes done in Environment it is showing quntity change on 18.11.2008

i.e after 15 days of GR and IR.

If Gr and IR for quantity 5 EA was done on 3-11-2008.

How system will allow to change quantity on 18-11-1008.

2) In some case it is not allowing to change quantity but we can change rate.

In this Po GR for full quantity was done but IR is pending ( all quantity).

Is it because of this or is there any another reason ?

Please help.

Thanks a Lot.

Prakash T.