title: Animating backgroundPosition works poorly on IE 8
body: <p>I tried to make jquery animate on the position of DIV image-background.
  I use the <a href="http://keith-wood.name/backgroundPos.html" rel="nofollow">http://keith-wood.name/backgroundPos.html</a> to do this effect.
  The animation slide on the x axis, with this positions:</p>
  
  <ol>
  <li>0</li>
  <li>50</li>
  <li>80</li>
  <li>110</li>
  <li>70</li>
  <li>50</li>
  </ol>
  
  <p>Its work fine, but on IE8 in all step its first of all go to x-position 0 and after that go to the right position.
  For example in step 4, its start on 0 and make slide animation to 110.
  Its wrong, because its should start on 80.</p>
  
  <p>How can i fix this?</p>