title: XDomainRequest problem
body: <p>I'm trying to make a asynchronous call to a service that returns json using XDomainRequest (IE8). The problem is that i always get an error (the onerror event is fired, and the responseText is always null), i'm using fiddler to check the response of the service and i seems right (I can see the json object returnig), this only happen in IE8 when using XDomainRequest, the same functionality implemented in JQuery works fine.</p>
  
  <p>Any clue would be appreciated. Thanks!</p>
  
  <p>P.S.: This is my javascript code:</p>
  
  <pre><code>.....
    if (jQuery.browser.msie &amp;&amp; window.XDomainRequest) {
      //Use Microsoft XDR
      var xdr = new XDomainRequest();
      xdr.open("post", url);
      xdr.onload = function () {
         alert("Loading");
         alert(xdr.responseText);
      };
      xdr.onsuccess = function() {
         alert("Success!");
         alert(xdr.responseText);
      };
      xdr.onerror = function() {
         alert("Error!");
         alert(xdr.responseText);
      };
      xdr.onprogress = function() {
         alert("Progress");
         alert(xdr.responseText);
      };
      xdr.timeout = 1000;
      xdr.send("data: " + escape(data));
      var response = xdr.responseText;
   } else .....
  </code></pre>