Setting ClassicLinkRoute breaks ability to set access rights to a page

Description

This was confirmed in a standard install of 7.5 with Alloy Templates (tested with WebForms version, but also reported to happen with MVC templates as well).

Steps to Reproduce:

1. Register ClassicLinkRoute as described at http://world.episerver.com/Documentation/Items/Upgrading/EPiServer-CMS/75/Breaking-changes/.
Put in Global.asax.cs:

      protected override void RegisterRoutes(System.Web.Routing.RouteCollection routes)
        {
            base.RegisterRoutes(routes);
            routes.Insert(0,ServiceLocator.Current.GetInstance<EPiServer.Web.Routing.ClassicLinkRoute>());
        }

2. Compile and navigate to admin mode.
3. Go to Set access rights.
4. If you click pages to which you wish to change access rights, you either get a 404 or navigate to the actual page, rather than seeing the access rights menu.