title: jquery ie8 scrollTop and offset issue
body: <p>I am attempting to position a very simple hover tool tip directly above a series of elements on a page. My positioning code works perfectly in FF, but in IE8 the positioning fails if the page is scrolled. I am compensating for scroll, but in IE8 it seems I have to double the number for it to work correctly.</p>
  
  <pre><code>$('.evidence_thumb').mouseenter(function() {
      var position = $(this).position();
      $top = ((position.top - $('#icon_tool_tip').height()) + $(window).scrollTop()) + 10;
      $left = ((position.left) + $(window).scrollLeft()) - 40;
      $('#icon_tool_tip').offset({ top: $top, left: $left });
  });
  </code></pre>
  
  <p>The margin of error in display with the above code is always exactly the amount of the scrollTop. I haven't tested with horizontal scroll, but I assume it will have the same issue.</p>