After moving our site to our host's IIS server, we are unable to log in through /index.php/login. After successful validation (incorrect credentials are still turned down), we are redirected to the home page with no active session.

If we navigate to /index.php/dashboard and login, everything works fine. This, obviously, isn't a great option for our non-admin users.

Even on a fresh installation of Concrete5, this holds true.

Anyone know what's wrong? What other information do I need to provide?