Purchase order history already inconsistent --> Quantity * * Value**

Hi experts,

Please note that I am trying to reverse a GR/IR account maintanence document.

But it throws the below error for a line item in the PO.

Purchase order history already inconsistent --> Quantity10,000- SET Value 3,96 AED

For this line item actually account maintanence was done on 30.10.09.And then

further GR has been done & IR also has been done.

Please advise in what circumstances system throw this error and how to reverse

the document now.

Regards,

Partha