title: jQuery dynamic added class gets not applied
body: <p>I've got a quite strange behaviour. I append a class at runtime but the class doesn't get applied (although it is there as I can see by debugging via firebug). Here is a fully (un-)functional example:</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;html&gt;
      &lt;head&gt;
          &lt;link rel='stylesheet' href='./jQuery/css/superfish/superfish.css' type='text/css' /&gt;
          &lt;link rel='Stylesheet' href='./jQuery/css/smoothness/jquery-ui-1.8.16.custom.css' type='text/css' /&gt;
          &lt;script type='text/javascript' src='./jQuery/js/jquery-1.6.2.min.js'&gt;&lt;/script&gt;
          &lt;script type='text/javascript' src='./jQuery/js/jquery-ui-1.8.16.custom.min.js'&gt;&lt;/script&gt;
          &lt;script type='text/javascript' src='./jQuery/js/jquery.ui.datepicker-de.js'&gt;&lt;/script&gt;
          &lt;script type='text/javascript' src='./jQuery/js/jquery-ui-timepicker.js'&gt;&lt;/script&gt;
          &lt;script type='text/javascript' src='./jQuery/js/jquery-ui-timepicker-de.js'&gt;&lt;/script&gt;
          &lt;script type='text/javascript'&gt;
              $(function () {
                  $('.DateTimePicker').datetimepicker({
                      stepMinute: 15
                  });
              });
          &lt;/script&gt;  
      &lt;/head&gt;
      &lt;body&gt;
          &lt;script type='text/javascript'&gt;
              function testMe() {
                  $("[id$=Working]").addClass('DateTimePicker');
              }
          &lt;/script&gt;
          &lt;input id="notWorking" type="text"&gt;
          &lt;input id="clickToTest" type="button" onclick="testMe()"&gt;
          &lt;input id="static" type="text" class="DateTimePicker"&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>