Freight Value in MIGO not as per PO

Hello,

  I am facing one issue in Subcontracting Purchase Order while receiving the Material through MIGO.

In PO I have maintained Freight Charges as 260 INR per TO. The PO Price maintained 1600 INR per TO.

I am receiving material from this PO since 2012 and upto 25.02.2014 freight charges were picked correctly as per PO.

I am facing this calculation problem since March 2014. I have checked the PO Changes and found there is no changes in PO which can affect this calculation of freight.

Please help me to sort out this issue asap.

Santosh Kumar