Cannot "Open containing folder"

[Vorpal]

Platform:

XP Pro (valid) SP2 + all patches to 2006-12-01

IE 7.0.5730.11IS

The problem manifests itself two ways:

:=In a search results window, right-clicking an item and choosing "Open containing folder" has no result

:=After downloading any file type, clicking "Open folder" has no result.

There are no error messages

There are no event log entries.

I've not used tweakui on this machine.

If I remember correctly (don't count on it), I have not added or modified any registry settings for Explorer.

My best guess is that it is a security setting somewhere, but I'm at a loss.

I've searched this site for "open containing folder" and come up dry (at least where this issue is concerned).

No luck elsewhere either.

Any ideas?

A happy & prosperous 2007 to all...

Vorpal