sencha + phonegap app is working fine in ios simulator but throws an error with desktop browser

First let me say thanks to those who answered my previous question, the help was awesome. :)

I have encountered another weird problem with my app in development.

My work in progress app is working fine in simulator but throws an error when 开发者_运维百科viewing in desktop browser.

the error code is

Uncaught TypeError: Cannot call method 'addCls' of null   sencha-touch-debug-w-comments.js:29830

I did some debugging and the error is produced when executing following line

listing.loginContentContainer = new Ext.Panel({
                id: 'loginContentContainer',
                fullscreen: true,
                layout: 'card',
                cardAnimation: 'slide',
                items: [signUpPanel, loginPanel, registrationPanel, menuBar],
                listeners : {
                             afterrender : function () { }
                            }
                 })

I'm initiating this panel in

initComponent: function () { }

and my index.js is as follow Ext.ns('listing');

Ext.setup({ //init
      //initial setup
      tabletStartupScreen: 'tablet_startup.png',
      phoneStartupScreen: 'phone_startup.png',
      icon: 'icon.png',
      glossOnIcon: true,

      onReady: function () {
      var app = new listing.App();


      }


      })

any idea? many thanks as always

Which desktop browser are you using ? (Sencha Touch is only compatible with webkit based browser) thus Safari and Chrome should work great (Firefox / IE / Opera probably won't).