title: css() and opacity.. following fadeIn() not working
body: <p>when I set opacity to 0 in css() the following fadeIn() doesn't work</p>
  
  <p>if I set opacity to 1 the <code>loader</code> element is showed but there will of course not be any fading in..</p>
  
  <pre><code>loader.css({
          top : ($(window).height() - loader.height()) / 2+'px',
          left : ($(window).width() - loader.width()) / 2+'px',
          opacity : 0
      })
      .fadeIn(1000);
  </code></pre>
  
  <p>if I use display:none it works!?</p>
  
  <pre><code>loader.css({
          top : ($(window).height() - loader.height()) / 2+'px',
          left : ($(window).width() - loader.width()) / 2+'px',
          display : 'none'
      })
      .fadeIn(1000);
  </code></pre>