title: OutputCache Bug with VaryByParam="None" with MVC RC refresh
body: <p>Came across to <a href="https://stackoverflow.com/questions/323458/asp-net-mvc-outputcache-doesnt-work-for-root-uri/325093">this defect</a> with ASP.NET RC refresh while using <code>VaryByParam=""</code> instead of <code>VaryByParam="None"</code>.</p>
  
  <p>Caching WORKS, but page <a href="http://www.yoursite.com" rel="nofollow noreferrer">http://www.yoursite.com</a> and <a href="http://www.yoursite.com/home/index" rel="nofollow noreferrer">http://www.yoursite.com/home/index</a> will be cached separately it seems. </p>
  
  <p>What is the difference between <code>VaryByParam=""</code> and <code>VaryByParam="None"</code>?</p>
  
  <p>edit : I mean <code>VaryByParam=""</code> not VaryByParam="*" cause the bug still exists with VaryByParam="*"</p>