title: jQuery Show not working if css class has display:none
body: <p>I have a class called loading like this:</p>
  
  <pre><code>.loading {
     display: none;
     vertical-align: top; 
     margin: 0; 
     padding: 0; 
     background: url('../images/shared/loading_16x16.gif') center center no-repeat; 
     width: 16px; 
     height: 16px;
  }
  </code></pre>
  
  <p>with following html snippet:</p>
  
  <pre><code>&lt;div id="loading" class="loading"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>and my jQuery code (on document ready):</p>
  
  <pre><code>$.ajaxSetup({
      beforeSend: function () {
          $("#loading").show().children().show();
      },
      complete: function () {
          $("#loading").hide().children().hide();
      }
  });
  </code></pre>
  
  <p>But <code>show()</code> is not working at all. Even if I trigger it from the chrome developer window.
  On the chrome developer window if I uncheck the <code>display: none</code> from the loading class then the tag appears.</p>
  
  <p>What's happening?</p>