Hi Derek,
To test, just do what I suggested. Open the site in two different browsers, IE8 and FF or Chrome.
Firefox is one of the browsers where the same session is used for all tabs and windows on the same workstation. IE8 is one of the browsers where the same session is sometimes used for all tabs and windows and sometimes not. I just tested on my workstation to verify what I have experienced before. The IE8 on my Vista is behaving exactly the same as FF. If I open a VWG application that requires logon in one Window and open it in another IE8 window, so that the logon screen is shown in both windows, and then login in one window and type something in the fields in the other window and click login button... it disregards the entered login info and just "jumps" directly into the app... exactly what it's supposed to do when both windows are using the same session.
So, again, open your site in IE8 and then in another browser and see what you get.
If you get different results in that case, you know this is what you are up against.
If that is the case, you will then need to search the internet for how to set your IE8 or your operating system to run two IE8 windows on seperate sessions, as I don't have that info at the moment.
Palli