Not saving

I have a user that is emailed his .doc files through dial up. Once the user comes to the office and logs on everything is O.K., then suddenly the .doc file doesn;t save at all. No file save icon, No file as Save works, Even closing the file doesn’t force the “Do you want to save…” prompt to pop up.
Tried Uninstalling/Reinstalling Office 2000 then Office XP enterprise edition. Both installations gave no solution to the problem.
Help would be greatly appreciated