Some users have more worksheets than others in same doucment

Hello,

We have users who access an Excel spreadsheet on a network drive. They
all access the file throughtout the day. A few users have added worksheets to
the spreadsheet and can see them when they re-enter the document later on.
Other users, however cannot see these added worksheets (Sheets 19-24, for
example). I checked their permissions and they all can modify the document.
My question is why can changes on the same document be made by one user, and
not be seen by another user- even a day or two later? I watched a user access
the proper folder and file- so I don't feel they are just accessing the wrong
file or a copy of it. I would appreciate any help on this.


--
Thank you,
Brian