ExtJs cannot scroll form (inside modal window) containing htmlEditors on IE6/Chrome

I have asked this same question in Sencha forum but didn't get any response. I just cant get the following code in IE6 nor Chrome but works perfectly on Firefox.

Here's the simple code:

Ext.onReady(function(){

 var window = new Ext.Window({
  title: 'Candidate CV',
  width : 900,
  height: 500,
  closeAction: 'hide',
  autoScroll : true,
  modal: true,
  defaultTyp开发者_开发知识库e : 'htmleditor',
  layout : 'form',
  items: [{
   fieldLabel: 'Professional Summary',
   name: 'summary',
   height : 300,
   width : 600,
   enableSourceEdit: false
  }, {
   fieldLabel: 'Career Objective',
   name: 'objective',
   height : 250,
   width : 600,
   enableSourceEdit: false
  },{
   fieldLabel: 'Accomplishments',
   name: 'accomplishments',
   height : 250,
   width : 600,
   enableSourceEdit: false
  }],
  buttons: [{
   text: 'Save' 
  }, {
   text: 'Cancel'
  }]
 });
    var editCV = Ext.get('show-window');
    editCV.on('click', function(){
     window.show();
    });

});

And the html code here.

<a id='show-window' href='#'>show</a>

I would like to know what am I missing here. You can try the code above and you will get the same result as mine.

Thanks