Extended Class of a formpanel doesn't show a frame

[JoepRonde]

I want to extend a formpanel with default frame = true. The code below defines a custom class for a floating, draggable formpanel with a frame. Creating an instance of this class doesn't show a frame. It seems that the initConfig doesn't set the frame to true. Why not?
Only when I create a instance of this class with a config object with frame = true it shows a frame.
Can anyone explain this?

Ext.define('MyForm', {
    extend: 'Ext.form.Panel',


    config: {
        title: 'This panel wants a frame',
        width: 200,
        height: 100,      
        frame: true, // setting frame to true should give a frame, but it doesn't
        floating: true ,
        draggable: true
    },
    constructor: function(config) {
        // Calling the constructor of the parent class.
        this.callParent(arguments);


        // Initializing the config settings.       
        this.initConfig(config);
    }
});


Ext.create('MyForm').showAt(10,10);
Ext.create('MyForm', {title: 'Now it has a frame', frame: true}).showAt(250,10);

[mitchellsimoens]

In Ext JS, you should really not use the config object. Some things may work but all in all, it's not fully implemented in the framework classes.

[JoepRonde]

I think you're right, but then Sencha should update the documentation on this. I got this example from the Ex.Class documentation.
http://docs.sencha.com/ext-js/4-1/#!/api/Ext.Class-cfg-config