Hi,

Steps to reproduce:

• Create a new MVC App
• Create an MVC Controller called Products.
• Add 2 controller actions, one called List which takes no parameters, one called View which takes an int Id
• Create 2 views for the 2 actions.
  
• Open Views/Shared/Site.Master
• Add 2 links next to Home and About
  • <%= Html.ActionLink<ProductController>(x => x.List(), "List Products") %>
  • <%= Html.ActionLink<ProductController>(x => x.View(1), "View Product 1") %>
• Test to make sure the app works (click on the 4 links in the header)
  
• Open Global.asax.cs
  
• There should be 2 Routes, add an extra Default to the first Route but not called controller, action, or id, e.g. page. (See below)
  
• Test the app again. Pay close attention to the URLs. The app is now broken.
  

The first route in Global.asax.cs should look like this...

      RouteTable.Routes.Add( new Route
      {
        Url = "[controller]/[action]/[id]",
        Defaults = new { action = "Index", id = (string)null, page = 1 },
        RouteHandler = typeof( MvcRouteHandler )
      } );

Simply adding page = 1 (or anything which isn't matched in the Url) breaks all the links which match this route.