title: jQuery $('.classname').length fails, but $.find('.classname').length works, why?
body: <p>My JavaScript module fails to find a particular DOM element with a classname using <code>$('.classname')</code> even when the element exists. </p>
  
  <p><code>$('.classname').length</code> returns 0, where as <code>$.find('.classname').length</code> returns 1.</p>
  
  <p>Website contains other JavaScript modules also. </p>
  
  <p>Can anyone help me to find why this is happening?</p>
  
  <p>My jQuery version is 1.7.1.</p>
  
  <p>To reproduce this 
  1- Go to avc.com<br>
  2- Open console.<br>
  3- Paste the following code in console.  </p>
  
  <pre><code>var head = document.getElementsByTagName("head")[0];  
  var script = document.createElement("script");  
  script.type = "text/javascript";  
  script.src = "//ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js";  
  script.async = true;  
  head.appendChild(script);
  </code></pre>
  
  <p>4- Try<br>
      <code>$('.pkg').length</code> and <code>$.find('.pkg').length</code>.</p>
  
  <p>Find the screen-shot from here <a href="http://i.imgur.com/4UDHz.png" rel="nofollow">http://i.imgur.com/4UDHz.png</a></p>
  
  <p>One more point, if you try this in some other websites, It works correctly.</p>