samba - Jan 2006 - double-clicking files gives error, yet file opens from application

Another strange problem:

A Windows 2000 client opens a file on a Samba share to which the logged
in user has access.

Files appear in the share window.

The files are, for example, Microsoft Word files with .doc extensions.
The system recognises them as such and the appropriate icon is displayed.

The user double-clicks on the icon and gets an error dialog saying
"Cannot find the file 'X:\<sharename>\<filename>.doc'
(or one of its
components). Make sure the path and filename are correct and that all
required libraries are available."

Yet, when the user opens the file from the application (e.g. starts
Word, chooses "open" from the File menu, browses to the share), the
file
opens without trouble.

I suspect this problem is not a new one. Does anybody have any advice?

-Stephen-