title: jQuery.ajax() - undefined data returned in IE9
body: <p>i have a very simple code:</p>
  
  <pre><code>$.ajax({
    cache: false,
    dataType: 'html',
    complete: function(jqXHR){
      console.log(jqXHR.responseText);
    },
    success: function(data){
      console.log(data);
    },
    url: 'http://follows.pl/pages/ajaxtest'
  });
  </code></pre>
  
  <p>it returns some text in ff, chrome and IE8, but in IE9 it shows twice "undefined".</p>
  
  <p>I've looked into developer tool in IE9, and it showing a normal response so the request works fine, response is fine, but variables are undefined</p>
  
  <p>headers of response:</p>
  
  <pre><code>Response    HTTP/1.1 200 OK
  Cache-Control   no-cache
  Content-Type    text/html; charset: UTF-8
  Pragma  no-cache
  </code></pre>
  
  <p>response</p>
  
  <pre><code>string(4) "test"
  </code></pre>