title: position fixed vertically with horizontal animation
body: <p>I want to achieve an effect similar to this: <a href="https://stackoverflow.com/questions/3303173/position-element-fixed-vertically-absolute-horizontally">Position element fixed vertically, absolute horizontally</a></p>
  
  <p>This can be seen working here: <a href="http://jsfiddle.net/thugsb/M2m58/" rel="nofollow noreferrer">http://jsfiddle.net/thugsb/M2m58/</a></p>
  
  <p>However, as in that fiddle, I want the parent to be able to be animated horizontally, and the fixed div to move horizontally with it (it's fixed so that when you scroll down the page it stays at a set height in the browser window). This works fine in FF (4/mac), but it fails to move in webkit. </p>
  
  <p>For some reason, if you animate the .positioner instead, the .fixed doesn't move until you inspect the element. Then it jumps into place. It's almost as if it's forgetting to update the display.</p>
  
  <p>Any ideas? Thanks!</p>