title: Incorrect position of tooltip only in new version of dojo 1.7
body: <p>When i updated my version of dojo from 1.6 to 1.7.1 i found an issue in the position of the tolltips in <code>ClusteredBars</code>. Even in the Dojo Toolkit SDK 1.7.1 this occurs.</p>
  
  <p>demo</p>
  
  <p><a href="http://jsbin.com/utesoz/2/edit" rel="nofollow">http://jsbin.com/utesoz/2/edit</a></p>
  
  <p>Any idea ? I think this problem is probably a bug     </p>