;;;the test website is not getting any session variables from the global.asa.
It is written about here and there to 'initiate session vars in the globa.asa file' - this is not required. Do you set any values there? this would be the only reason I would initiate them here. FYI - You can create them on any page.
;;;Is there something that needed to be set in IIS to have it reference the global.asa?
No I do not believe so, there is one to allow sessions. What version of IIS are you using? Have you tried creating one outside the global.asa file? Testing this will go along way in solving your problem.
;;;The only difference from the production version is that I have the site in a "test site" folder
This is fine, you can build the contents of your 'www' dir how ever you please.
;;;why would it have worked prior to the reboot
A reboot shouldnt change the properties of the web site or the machines default web site in any way, not sure on that one.
Wind is your friend