After about a week the Whole Tomato team gave me a solution that worked perfectly. Thanks for the support Mark, etc.
the answer is below
After doing some research, I came
across this page:
http://www.mztools.com/articles/2007/MZ2007009.aspx
that lists several possibilities why
it might not be showing up in the
add-in manager. One of them is:
"There is a reported problem that
happens when MSXML 6.0 is not
installed correctly. In this case the
Add-In Manager doesn't show any
XML-based add-in (using an .AddIn file
for registration). It shows only
registry-based add-ins. So, if the
Add-In Manager is empty when it should
show several installed add-ins (not
only yours), try reinstalling MSXML
6.0."
You might try reinstalling XSXML 6.0,
and see if that helps. Download link
is here:
http://www.microsoft.com/downloads/details.aspx?FamilyID=993c0bcf-3bcf-4009-be21-27e85e1857b1&displaylang=en
I'd certainly try that before
reinstalling VS2008.