Error Message: Pegging is not allowed when the material line is closed.

I have seen 2 other posts regarding this same error message but neither seem to match our situation. We are operating on APP9. User is attempting to move the work order to finished when this error message appears. All lines on the work order materials tab are either issued and/or closed. Due to costing issues in APP9, we create the purchase order and then peg the work order material line to the purchase order. As we tried to trouble shoot, we found the pegged work order material lines screen and noticed that some of the lines appeared on this screen. In all cases, the Qty pegged field was zero but the total pegged column matched the qty required column. Additionally we noticed the quantity available was a negative number. However, this didn’t match the data found on the material line in the work order nor did it match inventory part in stock. We are stuck on how to get the work order moved to finished status. Thanks for the help!