title: jQuery $(...).empty().append(...) slows down whole page after several executions
body: <p>I'm using <code>$('#...').empty().append(html)</code>-like construction to update  content on AJAX success.
  After 5-6 requests whole page goes slower and slower with each request (:hover takes more time to appear, JS slows down, etc.). This happens in any browser. The more content is loaded, the faster slowdown happens.</p>
  
  <p>I think I'm missing some cleanup somewhere.
  Any advice?</p>
  
  <p>Code:</p>
  
  <pre><code>query = function (uri, data) {
      $.ajax({
          url: uri,
          cache: false,   
          data: data,
          success: processResponse,
          method: data?'POST':'GET',
      });
      return false;
  }
  
  processResponse = function (data) {
      $('#rightplaceholder').empty();
      $('#rightplaceholder').append(data);
  }
  
  $('#button').click( function () { query('/foo'); } );
  </code></pre>
  
  <p>I've also tried disabling all JS not directly related to loading this fragment - with no luck.</p>