title: WebAuthBroker can't connect to service, but hand-posting in IE is succesful
body: <p>I have a Windows 8 app that builds a string and posts to https: using WebAuthBroker.  Relevant code is below.</p>
  
  <p>The problem is that WebAuthBroker takes this URI and cannot connect, but when I hand=post this URI into IE, it works fine.  </p>
  
  <p>Running VS2012 on Windows 8.
  In Package.appmanifest, have enabled Enterprise Authentication, Internet(Client), Internet(Client&amp;Server), Private Networks(Client &amp; Server), and Shared User Certificates.</p>
  
  <pre><code>            async Task AuthenticateAsync()
      {
          var requestUriStr = string.Format("{0}?client_id={1}&amp;response_type=token&amp;redirect_uri={2}", logonUriString, clientId, redirectUriString);
  
          requestUriStr += "&amp;scope=stream";
  
          var requestUri = new Uri(requestUriStr, UriKind.RelativeOrAbsolute);
          var redirectUri = new Uri(redirectUriString, UriKind.RelativeOrAbsolute);
  
          var result = await WebAuthenticationBroker.AuthenticateAsync(WebAuthenticationOptions.None, requestUri, redirectUri);
  
          if (result.ResponseStatus != WebAuthenticationStatus.Success)
          {
              throw new Exception("Login failed: " + result.ResponseErrorDetail);
          }
  </code></pre>