I have an Excel 2003 workbook designed and running on a Windows XP
system. The workbook makes extensive use of macros. It has been used
by about 15 different people, all running Office 2003 and Windows XP,
but now I have a problem with one user.

He is with a different company than mine, at quite a distance, and I
have to take his word for it that he is also using Office 2003 and
Windows XP. I've asked him to set his Excel security to "medium" so he
can enable the macros when he opens the workbook.

What is occuring is that when he opens the spreadsheet I email, all
the macros work fine, but when he saves it and reopens it, all the
macros and the formatting are gone. (The formatting includes cells of
various colors and hidden rows and columns. It's all wiped out.)

My first thought was that there was some kind of security feature of
his system that's wiping out the macros (although why the
formatting?). They are using McAfee, and their tech guy claims there
is nothing in their security that could be causing this.

My user has experimented quite a bit, and claims that he can fill in
data on every tab but one, save the workbook, and retrieve it
successfully. (There are about 20 tabs.) He thinks he even has it down
to a single cell. This makes no sense to me, as the cell is nothing
special.

I would greatly appreciate knowing if anyone has run into this before,
or has any ideas about what could be happening.

Thank you!