Your support, professionalism and patience are great!
Might I suggest a troubleshooting step for you to include in your support replies:
"Step 1: reboot your computer/server"
So, yes, I went through every config I knew of. Combed through my IIS settings and even changed the .NET Framework version at my localhost server level and nothing worked.
So, with my tail between my legs, I reluctantly allowed windows to apply the updates it has been complaining about for the last week then I went to lunch. When I returned I rebooted my computer, fired up VS, rebuilt and voila! It's working.
In my many years working on a windows machine you would think I would have known to reboot as a first rather than last resort :-).
Thanks for your help.