My BOM has items that are shown but then the quantity is a dash.  However lower down in the BOM (different number), the exact same item appears but with the quantity.  If I delete the row, not only do I have a missing item number, but it changes the quantity in the lower row.  If I click the arrows of the bom so that I get the part preview, the ghost line shows no part.  Anyone have any idea what is going on?  As a last note, combine like items does not cure this.  I dont even think it was "available", like its not recognizing it.  This is with bolts, nuts and washers from the toolbox.