Excel 2007

All I want to do is put a text box on a spreadsheet. When I click on
"Insert", the ribbon appears disabled. All items except Header & Footer are
grayed out.

The worksheet is not read-only.
There are no cells currently being edited.
Track Changes was turned on. I turned it off, saved and closed the
worksheet - still unavailable after reopening.

I've been using Excel since 1993. It's NEVER been this @#(*$& hard to
insert a textbox.

Thanks for your help.
--
Adios,
Clay Harryman