title: jquery ajax post json doesn't work in ie8
body: <p>I have this jquery code:</p>
  
  <pre><code>var sendInfo = {
      auth: {
          username: "janusz",
          password: "password"
      },
      func: "getCategories"
  };
  
  $.ajax({
      url: 'http://domainname/fcgi-bin/wgpa.fcgi',
      type: "POST",
      data: sendInfo,
      dataType: "json",
      contentType: "text/json; charset=utf-8",
      success: function (data) {
          //....
      }
  });
  </code></pre>
  
  <p>It works in Chrome, Firefox, IE11, but it fails in IE8.
  Doesn't say anything. And the request doesn't appear on server side either.</p>