I worked on a workbook yesterday and added a sheet to it. One of my
colleagues came in today she said one of her workbooks would not allow her to
modify the tab names of the worksheet or allow her to add a worksheet. I
opened up the file from the server and checked permissions, etc and saw that
these functions she mentioned were greyed out. I could not get them to work
but when I opened a different workbook of hers in another folder it worked as
normal.

Now the strange thing is, I just opened the workbook stored in my folder (on
the server) and now I can't modify tab names or add a worksheet!!! It's as if
my worksheet got infected. I am afraid to open any other workbooks. Any
suggestions. I can edit cells and same those edits, I just can't modify the
tab name or insert sheets or delete sheets. And how did this get transfered
to my workbook. I have discovered that several more workbooks in her folder
(on our server) are behaving the same.