title: MVCSiteMapProvider doesn't display SiteMapPath
body: <p>I have a simple sitemap:</p>
  
  <pre><code>&lt;mvcSiteMapNode title="Projects" controller="Projects" action="Index"&gt; &lt;!--This wraps the entire site since Projects Index is the homepage--&gt;
      &lt;mvcSiteMapNode title="Projects" controller="Projects" action="Index"&gt;
        &lt;mvcSiteMapNode title="Project" controller="Projects" action="Details"&gt;
          &lt;mvcSiteMapNode title="Session" controller="Session" action="DetailsNew" /&gt;
          &lt;mvcSiteMapNode title="Edit Session" controller="Session" action="Edit" /&gt;
        &lt;/mvcSiteMapNode&gt;
      &lt;/mvcSiteMapNode&gt;
      &lt;mvcSiteMapNode title="My Account" controller="Account" action="ChangePassword" /&gt;
      &lt;mvcSiteMapNode title="Admin" controller="Admin" action="Index" &gt;
        &lt;mvcSiteMapNode title="Create User" controller="Admin" action="AddUser" /&gt;
        &lt;mvcSiteMapNode title="Manage Users" controller="Admin" action="Users" /&gt;
      &lt;/mvcSiteMapNode&gt;
    &lt;/mvcSiteMapNode&gt;
  </code></pre>
  
  <p>When I put <code>@Html.MvcSiteMap().SiteMapPath()</code> on my Project Details page, nothing displays. Ideas?</p>