PO Receipt of Goods?  Has the transaction been Printed and Updated?  If so, do a PO Return of Goods.  If not, you should be able to delete from PO Receipt of Goods Entry.  

We did get the situation resolved. The issue was that the item was received on the PO and then change to be a serialized item. So the item was in the system with no way to change it without a serial number. We had several of these items in inventory, with serials attached, so our cost accountant removed the problem child and added those instead. Thanks for your help!