title: relaxedUrlToFileSystemMapping="true" doesn't work
body: <p>I have a route in my mvc (.net 4) application, which is supposed to appear like it's retrieving a mp3 file from the server. To obtain that, I'm doing like this:</p>
  
  <pre><code> routes.MapRoute(
                  "DownloadPodcast", 
                  "download/{action}/{episodeId}/{foo}", 
                  new { controller = "Files", action = "DownloadPodcast", episodeId = UrlParameter.Optional }
              );
  </code></pre>
  
  <p>This works fine on localhost, but when I publish it to my IIS6 server, I get an 404 error. I've googled it a lot, and everybody says that I should add this to my web.config:</p>
  
  <pre><code>&lt;httpRuntime relaxedUrlToFileSystemMapping="true" /&gt;
  </code></pre>
  
  <p>BUT - it doesn't seem to have any effect :(</p>