title: Highcharts 4.0.4 Export Issue on Internet Explorer
body: <p>I am using Highcharts 4.0.4. I have made some changes to export feature by applying the following code:</p>
  
  <pre><code>exporting: {
                buttons: {
                            contextButton: {
                                              enabled: false
                                          },
                                          exportButton: {
                                              text: 'Download',
                                              menuItems: Highcharts.getOptions().exporting.buttons.contextButton.menuItems.splice(2)
                                          },
                                          printButton: {
                                              text: 'Print',
                                              onclick: function () {
                                                  this.print();
                                              }
                                          }
                                      }
                                  }
  </code></pre>
  
  <p>The above code shows the Print and Download button instead of default export button. The print button performs the print function, while the download button shows the drop down to export JPG, PNG, SVG etc. </p>
  
  <p>This code is working fine on Chrome and Firefox but not on IE 10, any idea what I am doing wrong here? Somehow Highchart's default export feature is working fine but this updated code is not working.</p>
  
  <p>Any idea?</p>
  
  <p>Thanks.</p>