Mike:
Ran into the same problem. My fix (unique to me - may not
apply to you) DON'T DOWNLOAD DRIVERS FROM MICROSOFT. I
have a NVIDA RIVA TNT2 M64 (Dell) adapter. After
downloading a new (Windows Update) driver, Visio fonts,
templates, etc. screwed up. AFter much knashing of teeth,
hitting the computer, de-installing and re-installing
Visio, all to no avail, I reloaded the old driver from the
Dell support website. Visio is now happy. Microsoft, of
course, being the money hungry folks they are, probably
won't read this, and to talk to them directly you have to
give them money, promise your first born child, etc, so am
unsure how to provide meaningful feedback to them. Hope
this helps.