title: ExtJS problem with Extended Window, shows in FF not in IE
body: <p>I get this irritating error message in IE, 'Events is empty or not an object'.</p>
  
  <p>This is my Extended window:</p>
  
  <pre><code>windowKandidaatInfo = Ext.extend(Ext.Window, {
  id: 'windowKandidaatInfo',
  title: 'Kandidaatinfo',
  border: true,
  bodyStyle: 'padding: 5px;',
  layout: 'fit',
  width: 800,
  height: 600,
  pers_id: 0,
  modal: true,
  viewConfig: {forceFit: true},
  constructor: function(pers_id){
      this.pers_id = pers_id;
      windowKandidaatInfo.superclass.constructor.call(this);
  },
  activeTab: function(panel, tab){
      tab.getForm().load({
          url: '/kandidaten/get_kandidaat_info/' + panel.pers_id + '/',
          method: 'get'
      });
      tab.getForm().on({
          actioncomplete: function(form, event){
              if(event.type == "load"){
                  //Data loaded
              }
          }
      })
  },
  spacerCol: {
      colspan: 2,
      border: true,
      width: 1,
      height: 25,
      align: 'left'
  },
  combCountry: {
      xtype: 'combo',
      name:'land',
      fieldLabel: 'Land',
      store: new Ext.data.JsonStore({
          url: '/index/get_countries/',
          method: 'get',
          root: 'data',
          fields: [{name:'id'},{name:'naam'}],
          autoLoad: true
      }),
      displayField: 'naam',
      valueField: 'id',
      triggerAction: 'all',
      selectOnFocus: true,
      typeAhead: true
  },
  combGeslacht: {
      xtype: 'combo',
      name:'geslacht',
      fieldLabel: 'Geslacht',
      store: new Ext.data.JsonStore({
          url: '/index/get_geslacht/',
          method: 'get',
          root: 'data',
          fields: [{name:'naam'}],
          autoLoad: true
      }),
      displayField: 'naam',
      triggerAction: 'all',
      selectOnFocus: true,
      typeAhead: true
  },
  combBurgelijkeStaat: {
      xtype: 'combo',
      name:'burgelijke_staat',
      fieldLabel: 'Burgelijke staat',
      store: new Ext.data.JsonStore({
          url: '/index/get_burgelijke_staat/',
          method: 'get',
          root: 'data',
          fields: [{name:'naam'}],
          autoLoad: true
      }),
      displayField: 'naam',
      triggerAction: 'all',
      selectOnFocus: true,
      typeAhead: true
  },
  combProfessions: {
      xtype: 'combo',
      name:'beroep',
      fieldLabel: 'Beroep',
      store: new Ext.data.JsonStore({
          url: '/index/get_beroepen/',
          method: 'get',
          root: 'data',
          fields: [{name:'beroep'}],
          autoLoad: true
      }),
      displayField: 'beroep',
      triggerAction: 'all',
      selectOnFocus: true,
      typeAhead: true
  },
  initComponent: function(){
  
      Ext.apply(this, {
         items: new Ext.TabPanel({
             id: 'tabGeneral',               
             pers_id: this.pers_id,
             activeTab: 0,
             items: [
                 {
                      title: 'Algemene info',
                      layout: 'table',
                      xtype: 'form',
                      frame: true,
                      bodyStyle: 'padding: 5px;',
                      viewConfig: {columns: 2, forceFit: true},
                      items: [
                          {
                              column: .5,
                              width: 400,
                              layout: 'form',
                              items: [
                                  {
                                      layout: 'table',
                                      columns: 2,
                                      items: [
                                          {
                                              layout: 'form',
                                              style: 'margin-right: 5px;',
                                              items: [
                                                  { xtype: 'textfield', width: 40, name: 'voorletters', fieldLabel: 'Voorl/ voornaam'},
                                              ]
                                          },
                                          {
                                              layout: 'form',
                                              items: [
                                                  { xtype: 'textfield', width: 200, name: 'voornaam', hideLabel: true}
                                              ]
                                          }
                                      ]
                                  },
                                  { xtype: 'textfield', name: 'achternaam', fieldLabel: 'Achternaam'},
                                  { xtype: 'textfield', name: 'adres', fieldLabel: 'Adres'},
                                  {
                                      layout: 'table',
                                      columns: 2,
                                      items: [
                                          {
                                              layout: 'form',
                                              style: 'margin-right: 5px;',
                                              items:[
                                                  {xtype:'textfield', width: 60, name:'postcode', fieldLabel:'Postcode/ plaats'}
                                              ]
                                          },
                                          {
                                              layout: 'form',                                                
                                              items: [
                                                  {xtype:'textfield', width: 200, name:'plaats', hideLabel: true}
                                              ]
                                          }
                                      ]
                                  },
                                  this.combCountry,
                                  this.spacerCol,
                                  { xtype: 'textfield', value: '1900-01-01', format: 'Y-m-d', name: 'geb_datum', fieldLabel: 'Geb. datum'},
                                  { xtype: 'textfield', name: 'bsn_nummer', fieldLabel: 'Bsn nummer'},
                                  this.combProfessions,
                                  this.spacerCol,
                                  { xtype: 'textfield', name: 'bedrijfsnaam', fieldLabel: 'Bedrijfsnaam'},
                                  { xtype: 'textfield', name: 'kvk_naam', fieldLabel: 'KvK naam'},
                                  { xtype: 'textfield', name: 'kvk_land', fieldLabel: 'KvK land'}
                              ]
                          },
                          {
                              column: .5,
                              width: 400,
                              layout: 'form',
                              items: [
                                  { xtype: 'textfield', name: 'telefoon', fieldLabel: 'Telefoon'},
                                  { xtype: 'textfield', name: 'mobiel', fieldLabel: 'Mobiel'},
                                  { xtype: 'textfield', name: 'fax', fieldLabel: 'Fax'},
                                  { xtype: 'textfield', width: 200, name: 'email', fieldLabel: 'E-mail'},
                                  { xtype: 'textfield', width: 200, name: 'website', fieldLabel: 'Website'},
                                  this.spacerCol,
                                  { xtype: 'textfield', name: 'geb_plaats', fieldLabel: 'Geb. plaats'},
                                  this.combBurgelijkeStaat,
                                  this.combGeslacht,
                                  this.spacerCol,
                                  { xtype: 'textfield', name: 'btw_nummer', fieldLabel: 'BTW nummer'},
                                  { xtype: 'textfield', name: 'kvk_plaats', fieldLabel: 'KvK plaats'},
                                  { xtype: 'textfield', name: 'kvk_nummer', fieldLabel: 'KvK nummer'}
                              ]
                          }
                      ]
                 },
                 {
                      title: 'Adres info',
                      xtype: 'form',
                      layout: 'form',
                      bodyStyle: 'padding: 5px;'
                 },
                 {
                      title: 'Contact info',
                      xtype: 'form',
                      layout: 'form',
                      bodyStyle: 'padding: 5px;'
                 }
             ],
             listeners: {
                 tabchange: this.activeTab
             }
         })
      });
      windowKandidaatInfo.superclass.initComponent.call(this);
  },
  show: function(){
      windowKandidaatInfo.superclass.show.apply(this, arguments);
  }
  </code></pre>
  
  <p>});</p>
  
  <p>this is how i call it in a simple JS function:</p>
  
  <pre><code>function showWindow(){
  var win = new windowKandidaatInfo(id);
  if(win){
      win.show();
  }}
  </code></pre>
  
  <p>Why o why is it showing in FF but not in IE?</p>