Exchange rate Issue in Purchase order

Dear Sir,

We have maintained exchange rate in Ob08 that is   80.40 INR

But when we are creating PO system is taking 44.17000

Pls. Advice

I have seen lots of threads still i am not able to get Answer

http://wiki.scn.sap.com/wiki/display/ERPFI/Exchange+Rate+Determination

Thanks in advance

Regards

SP