CP sp2/ excel 2003 sp3

I have a user that opens a excel worksheet - and it has no data - just a
letter or two on the page. We cannot move around at all, but the application
is NOT forzen.
I tried to open it with repair and it could not get the data. I tried
extract and it was unusable.

When I log into the same machine with another account the same excel file
opens without a problem. I tried reinstalling office, then removing, reboot,
installing excel.
Same problem. So I have the user create a new copy and he can get in, then
the problem happens again after a certain period of time. The user can log
into another machine and open the file without a problem. What could be
causing this and how could I address it.