My company has two identical applications - one on an in-house server, one hosted by a 3rd party hosting company.

I'm using IE7 and can successfully access the app on our site. But when I use IE7 to attempt to access the app on the other site, I'm redirected to the app's *incompatible browser* custom error page. I can access the app successfully on both sites using IE6. The app has an accepted browser ini file that explicitly allows IE6 (and all previous browser versions) but does not mention IE7 at all.

I know that the hosting company doesn't have the same set of standards and policies that we do internally, and this explains the discrepancy. How can I determine exactly what discrepancy is causing this specific scenario? IIS settings a good place to start?

Both servers run Windows Server 2003.