bug tooltip stickyTracking

HTML

<script src="http://code.highcharts.com/highcharts.js"></script>
<script src="http://code.highcharts.com/modules/exporting.js"></script>

<div id="container" style="min-width: 400px; height: 400px; margin: 0 auto"></div>

JavaScript

$(function () {
    var chart;
    $(document).ready(function() {
        chart = new Highcharts.Chart({
            chart: {
                renderTo: 'container',
                type:'pie'
           
            },
             plotOptions: {
                pie: {
                     stickyTracking:true
                }
            },
            series: [{
    
                name: 'Browser share',
                data: [
                    ['Firefox',   45.0],
                      ['IE',       26.8],
                       ['Chrome',      12.8],
                      ['Safari',    8.5],
                    ['Opera',     6.2],
                    ['Others',   0.7]
                ]
            }]
        });
    });
    
});