title: Authorizer.IsAuthorized is returning false after I have authenticated
body: <p>I just started working with the Facebook SDK this weekend.  I'm trying to integrate Facebook into a site.  I followed the samples and documentation and got the Facebook Login button along with displaying "faces" fairly quickly (nice Toolkit).</p>
  
  <pre><code>&lt;fb:login-button autologoutlink="true" perm="email"  show-faces="true" width="200" max-rows="1"&gt;&lt;/fb:login-button&gt;
  </code></pre>
  
  <p>I would like to check if the user has already been authenticated (via Facebook). This is no different than what I've seen in many of the samples. The issue, I'm having is that in my Page_Load, the <code>authorizer.IsAuthorized</code> is returning False even after I authenticate (my profile picture is displayed as well).  Is there something that I'm missing?</p>
  
  <pre><code>protected void Page_Load(object sender, EventArgs e)
  {
  
      try
      { 
          Facebook.FacebookApp app = new Facebook.FacebookApp();
  
          Facebook.Web.Authorizer authorizer = new Facebook.Web.Authorizer(app);
  
          if (authorizer.IsAuthorized())
          {
  
          }
          else 
          {
  
          }
      }
      catch (Exception ex)
      {
      }
  }
  </code></pre>