Remaining quantity Negative on Batch Order Co-products

Hi

I have observed an issue, where on this form PmfProdCoBy the co-product remaining quantity is showing negative value.

Click Production control/Common/Production orders/All production orders/ Production details/ Co-products/ Quantity Tab

Click Production control/Common/Production orders/All production orders/ Production details/ Co-products/ Quantity Tab/ 

Select the item then click on Inventory menu and click transactions.

In what case this can happen where for a co-product line, system is showing issue status as On Order(it should be receipt status with on order). Not able to end production order because of this issue.