Trying to Move Classic ASP App from IIS 6 to IIS 7.5

I've been at this for hours now. The application works fine on the original IIS 6 server. The application uses pass-through authentication with impersonation (which I guess means the ASP code runs as the authenticated user), but no matter what I do it always fails, except when I use basic authentication in which case it works perfectly fine, so there's obviously something not working correctly with pass-through. It actually logs the user in (you can see this on any 404 error page where it shows the logged in username), but it doesn't seem to be running the ASP code as that user.

The application always fails at the same line with the same error "80072030". The code is:

grouppath = "LDAP://cn=Leave Roster Admins,ou=Admin Security Groups,ou=Security Groups,ou=Groups,ou=MyOrg,dc=myorg,dc=local"
Set objGroup = GetObject(grouppath)

Obviously, the user querying LDAP should be the authenticated user. Though it seems impersonation is not working with Windows Authentication, though it works with basic authentication. It just fails to make any sense.

So basically, what would permit basic authentication from working perfectly, but windows authentication to not? It doesn't seem to make any sense.

EDIT: Trust a Microsoft website to not support Chrome. Have to put in line breaks manually.