title: DotNetOpenAuth Expected IProtocolMessage message
body: <p>I'm trying to request an authentication token:</p>
  
  <pre><code>public static void RequestAuthorization(WebConsumer consumer)
  {
      var extraParams = new Dictionary&lt;string, string&gt; { 
          { "oauth_token", string.Empty},
          { "oauth_callback", "http://www.ihighfive.com/" },
      };
  
      var req = consumer.PrepareRequestUserAuthorization(callback, extraParams, null);    
      consumer.Channel.Send(req);
  }
  </code></pre>
  
  <p>Problem is, when I run .PrepareRequestUserAuthorization() I get the following error</p>
  
  <blockquote>
    <p>Expected IProtocolMessage message but received no recognizable
    message.</p>
  </blockquote>
  
  <p>Inspecting the request/response with Fiddler, I can see that the response returns(values obfusticated):</p>
  
  <pre><code>{ "oauth_token" : "this-is-the-oauth-token", 
  "oauth_token_secret" : "this-is-the-oauth-secret-token", 
  "oauth_callback_confirmed" : true, 
  "urlToSendUserTo" : "http://blah.blah.com/api/OAuthAuthorizeToken.aspx?oauth_token=token-value-is-really-long"}
  </code></pre>
  
  <p>To me, this appears to be a good response. If I visit the urlToSendUserTo, it works, and then passes me through to my initial callback url. So I guess DNOA is having problems parsing the response, but I can't see why.</p>