You might try forcing Word to re-write its registry keys for the affected user.

With Word closed, Go to Start and insert the following command:
"C:\Program Files\Microsoft Office\Office\winword.exe" /regserver
Press Enter. This will cause Word to rewrite all its registry keys and to reassociate itself with its documents and templates.

If that fails, the issue remains most likely to be a network configuration/permissions one, rather than a Word one.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]