Report Builder: How do I delete old dynamic control now referred to as "#REF"?

I created a Segment control using Report Builder's Request Wizard. The Wizard referred to it by cell address, like "SheetA1".  I then cut the control from the Excel file. There was no option to delete it. The Wizard then referred to the Segment control within the Segment selection as #REF and I can find no way to delete the obsolete choice from the drop down. So what is the proper way to delete obsolete segment control references? Thanks, BK