title: jspdf first PDF page is blank
body: <p>Im trying to get my jspdf to not save a blank page PDF. I been trying many examples, but nothing works :(. My table content is saved correct, with a image on the second page of the PDF, but my first page is blank.</p>
  
  <pre><code>var pdf = new jsPDF('o', 'pt', 'a6');
  //pdf.autoTable(this.columns, this.data);
  //var width = pdf.internal.pageSize.width;    
  //var height = pdf.internal.pageSize.height;
  pdf.addPage('1800','900');
  pdf.addImage(imgData, 'PNG', 120, 40, 120, 100);
  pdf.setTextColor(0,0,0);
  pdf.text(120, 20, 'BOOKINGS');
  pdf.setFontSize(22);    
  // 'o', 'pt', 'a4'
  // 'p', 'pt', 'letter'
  // source can be HTML-formatted string, or a reference
  // to an actual DOM element from which the text will be scraped.
  source = jQuery('.dataTables_wrapper')[0];
  // we support special element handlers. Register them with jQuery-style 
  // ID selector for either ID or node name. ("#iAmID", "div", "span" etc.)
  // There is no support for any other type of selectors 
  // (class, of compound) at this time.
  specialElementHandlers = {
      // element with id of "bypass" - jQuery style selector
      '#bypassme': function (element, renderer) {
          // true = "handled elsewhere, bypass text extraction"
          return true
      }
  };
  margins = {
      top: 120,
      bottom: 0,
      left: 0,
      width: 2000
  };
  // all coords and widths are in jsPDF instance's declared units
  // 'inches' in this case
  pdf.fromHTML(
  source, // HTML string or DOM elem ref.
  margins.left, // x coord
  margins.top, { // y coord
      'width': margins.width, // max width of content on PDF
      'elementHandlers': specialElementHandlers
  },
  
  function (dispose) {
      // dispose: object with X, Y of the last line add to the PDF 
      //          this allow the insertion of new lines after html
          pdf.save('bookings.pdf');
  }, margins);
  </code></pre>
  
  <p>}</p>