title: d.select is not a function
body: <p>I'm trying to use the drilldown pie chart (see <a href="http://jsfiddle.net/Lzhm6/16/" rel="nofollow noreferrer" title="jsfiddle">jsfiddle</a>).
  I found this at following posts answer:
  <a href="https://stackoverflow.com/questions/7422616/highcharts-pie-chart-drilldown-not-showing-on-third-drill">Highcharts Pie Chart Drilldown not showing on third drill</a></p>
  
  <p>This fulfills my need perfectly, but I get an error when I click on pie slice to drilldown to next level. The error is:
  <code>d.select is not a function</code> i.e. at <code>d.select(null,a.ctrlKey||a.metaKey||a.shiftKey)</code></p>
  
  <p>Could you please help me out????</p>
  
  <p>Thanks 
  JC</p>