title: Highcharts Crosshairs not working
body: <p>I have what I'd consider a relatively simple Highcharts chart that I want to use shared crosshairs, but for some reason, I can't get my tool tip to work properly.  Here is my javascript code:</p>
  
  <pre><code>var myChart = new Highcharts.Chart({
      chart: {
          renderTo: 'container',
          width: '675',
          height: '400',
      },
      toolTip: {
          crosshairs: {
              width: 2,
              color: 'gray',
              dashStyle: 'shortdot'
          },
          shared: true,
          enabled: true
      },
  
      xAxis: {
          title: {
              text: 'Date',
              align: 'middle',
              margin: 15,
          },
          reverse: false,
          type: 'datetime',
          opposite: false,
      },
      yAxis: [{
  
          title: {
              text: '% Change',
              align: 'middle',
              margin: 15,
          },
          reverse: false,
          opposite: false,
          },
      {
          title: {
              text: 'actual amount',
              align: 'middle',
              margin: 15,
          },
          reverse: false,
          opposite: true,
          }, ],
      title: {
          text: 'Comparison Chart',
          align: 'center',
          margin: 15,
      },
      series: [{
          pointInterval: 86400000,
          name: 'Your actual amount',
          type: 'spline',
          yAxis: '1',
          color: '#4572A7',
          data: [[1291248000000, 4140],
                                                      [1291334400000, 342],
                                                      [1291420800000, 56],
                                                      [1291507200000, 58],
                                                      [1291593600000, 712],
  
                                                      ]},
      {
          pointInterval: 86400000,
          dashStyle: 'ShortDashDot',
          name: 'Other\'s %',
          type: 'spline',
          yAxis: '0',
          color: '#89A54E',
          data: [[1291248000000, 47.02],
                                                      [1291334400000, -28.68],
                                                      [1291420800000, -59.98],
                                                      [1291507200000, 182.14],
                                                      [1291593600000, -12.81],
  
                                                  ]},
      {
          pointInterval: 86400000,
          dashStyle: 'ShortDash',
          name: 'Your %',
          type: 'spline',
          yAxis: '0',
          color: '#AA4643',
          data: [[1291248000000, 246.73],
                                                      [1291334400000, -91.74],
                                                      [1291420800000, -83.63],
                                                      [1291507200000, 3.57],
                                                      [1291593600000, 1127.59],
  
                                                  ]},
                               ],
  });
  </code></pre>