v7.4 Sales Order - Phantom Line - Exists but Blank

I have a Sales Order that I'm trying to close but cannot.   There are two lines in the SO.  You can see this correctly in all Inventory Transaction Tables and Explorer View (Sales Order Lines).  However, on the enter Sales Order screen.   It shows three Line,.   The 2nd line is Blank but Grayed Out. 

Can I get some pointers on how to fix?