gmail contextual gadget makeRequest call responds with Internal Server Error

I am building a google contextual gadget in it i use the following code to load a page:

var params = {};
 url = "http://example.com:2057/tasks/create";
  params[gadgets.io.RequestParameters.CONTENT_TYPE] = gadgets.io.ContentType.JSON;
  params[gadgets.io.RequestParameters.AUTHORIZATION] = gadgets.io.AuthorizationType.SIGNED;
  params["OAUTH_SERVICE_NAME"] = "HMAC";
  params[gadgets.io.RequestParameters.METHOD] = gadget开发者_C百科s.io.MethodType.GET;

  gadgets.io.makeRequest(url, function(response) 
  { 
    if (response.data && response.data.RedirectUrl)
        HandleLogin(response.data.RedirectUrl);
    else if(response.text)
    {
        showOneSection('main');
        $('#main').append(response.text);
    }
    else 
      ShowDebug(response);
  }, params);

The call does not reach my server. and when i try reaching the url in a browser it returns fast.

what can be the problem? how can i trouble shoot it?

Thanks

I finally found the problem. when making a signed request you have to first obtain a consumer key + secret key. see http://www.google.com/support/forum/p/apps-apis/thread?tid=31db71169fb6fc77&hl=en you can do that here: https://www.google.com/gadgets/directory/verify without the keys google is unable to sign the request (although one would expect a proper error message).