Can you rightclick on an empty spot on any toolbar and choose customize?
Can you get to customize via View|Toolbars|Customize?
If you can, how about resetting that worksheet menubar back to factory defaults.
If you get to the customize dialog|toolbars Tab
select worksheet menubar and then click the reset button.
If you can't get to it, you can run a little line of code to reset it.
hit alt-f11 (to get to the VBE, where macros live)
hit ctrl-g (to see the immediate window)
type this and hit enter:
application.CommandBars("worksheet menu bar").Reset
Then alt-f11 back to excel to see if you've reset it.
(You'll have to re-customize any changes you've made to this toolbar, though.)
