This issue is limited to one user.
I have already run several repairs on Excel and even set up a new computer.
Still the problem happens.
Every couple of months, an Excel file which she is working on will get reverted to a version of one or two modifications ago.
Checking event viewer logs and file server logs show nobody else modifying the file other than the user.
The issue is very simliar to this: http://www.tek-tips.com/viewthread.cfm?qid=1033561
which was never resolved.
I'm inclined to think this is a user-caused issue. It is happening to no one else.
So I guess my question is both technical and non-technical.
On the technical side, is there anything else I can check which could be causing this? Maybe Excel is caching older version which, for some reason, then overwrite the new version?
On the non-technical side, what best practices can I show the user so, if the problem is being caused by something they're doing, it will stop occurring?