error when viewing Word docs from WebDesk Pro

Grundy

TeamSite 6.1 on Windows 2000 SP4. Client browser IE 6.

We are finding that users cannot view Word docs by clicking on the filename in WebDesk Pro. VisualPreview for .doc files has been disabled in iw.cfg, and it works fine to view them from CC Std or CC Pro.

When attempting to preview from WebDesk Pro, they get the following error message:

Internet Explorer cannot download File.doc from ServerName.
Internet Explorer was not able to open this Internet Site. The requested site is either unavailable or cannot be found. Please try again later.

This exact symptom is described in Iwov KB article 50060, but all this article offers for solution is a reference to Microsoft KB article 317208, which says that the problem results from a content expiration setting in IIS. This cannot be the problem in our case because we do not have content expiration enabled at all in our content webserver.

Does anyone know of other possible causes and/or workarounds?