title: Casperjs visible() returns true while jquery is(':visible') returns false for the same selector
body: <p><code>casper.visible('#percent_med_pickup');</code> returns true, while the following code with the same selector returns false:</p>
  
  <pre><code>casper.evaluate(function(){
  
  return $('#percent_med_pickup').is(':visible');
  });
  </code></pre>
  
  <p>Aren't both the same?</p>