title: setAutoGrow: other pages should "shrink" again
body: <p>I'm using <code>FB.Canvas.setAutoGrow(7);</code> to grow my page (page=highscore table so needs to grow).</p>
  
  <p>However, when I go back to other pages, the canvas stays grown, but it should adapt to the new content, off course... Basicly, it needs to shrink again.</p>
  
  <p>I tried setSize but that didn't work.</p>
  
  <p>Anyone who can help me? I've been looking for hours...
  Thanks a lot!!!</p>