Uncaught TypeError: Cannot read property 'containerBox' of null

[lasseok]

Hi

I have a panel where I need to create a form when the user clicks a button. But when I try to do that, I get the following error in Chrome's console:

Uncaught TypeError: Cannot read property 'containerBox' of null
   Ext.Container.Ext.extend.onFieldFocussencha-touch-debug.js:20996
   fieldEventWrap.focussencha-touch-debug.js:20937
   firesencha-touch-debug.js:979
   Ext.util.Observable.Ext.extend.fireEventsencha-touch-debug.js:595
   Ext.form.Text.Ext.extend.onFocussencha-touch-debug.js:27592
   anonymous:5
   (anonymous function)

My code is simple:

//[...] Other panel stuff [...]

//When the user click a button:
contactScreen.add({
	cls: 'editForm',
	itemId: 'editForm',
	xtype: 'formpanel',	
	items: [{
		xtype: 'textfield',
		itemId: 'name',
		name: 'name',
		label: 'Name'
	}]
});

//[...] Other panel stuff [...]

If I just add a formpanel to the panel's items array before render everything is fine, unless I specify the hidden attribute of the formpanel. If I then call the show() method at runtime, I once again get the above error.

I'm mystified, so I would really appreciate some help!

[lasseok]

Anyone?