Problem with TabPanel, NavView & List

[Oden]

Hello i am new with sencha touch and i need your help.

I have a TabPanel where the 1st item is a navigation.view witch loads a list.
For some reason nothing loads in the screen (blank page) and no errors in the console.

Here is a link http://www.senchafiddle.com/#73IvY

Just to mention that in app.js if I change

var panel = Ext.create('MyApp.view.MainPanel');

to this:

var panel = Ext.create('MyApp.view.CategoriesList');

the list loads without any problem.

Rly i cant find what i am doing wrong, testing 2 days in a row. Tnx for your time!

[mitchellsimoens]

What is the parent of the list? What layout is it using?

[Oden]

I'am missing something? I'll the code i use is on that link.
What i need to put on the list? Sir, can you give me more directions plz?