I have several workbooks in which I had some sheets hidden. Now suddenly, I
am unable to unhide them. I am also unable to hide additional sheets.
The method I am used to is - select sheet, go to Format, Sheet, and
Hide/Unhide. But the Hide and Unhide options simply aren't there in the
drop-down menu any more. By looking at the properties I can see that the
hidden sheets are still in the workbook, but I just can't find any way to get
at them.

It's possible that my company's IT department changed our version of Excel.
I don't know how I could find out if they did though. Could that be the
source of the problem?

Any suggestions on how to make my hidden sheets come back would be
appreciated.