setMasked don't work on iPhone

Hello,

I'm creating an app, that load dynamically items on a store.

During the load I push the masked view on Viewport.

It's working when I'm trying the app on Firefox Browser, but when I try on my iphone, there is nothing masked view...

On the main.js I've add two functions :

Code:

function mask(texte) {
    Ext.Viewport.setMasked({
        xtype: 'loadmask',
        message: texte
    });
}
function unmask() {
    Ext.Viewport.unmask();
}

And I call them inside other functions on main.js :

Code:

function schedule(ladate) {
    mask('Loading...');
    start = new Date();
    ....
    unmask();
}

I've tried to set loadmask in the view like this :

Code:

itemTpl: new Ext.XTemplate(
    ...
),
masked: {
       xtype: 'loadmask',
       message: 'Loading...'
 },

But it's always work on Firefox, not on iPhone...

How can I do this please ?



setMasked don't work on iPhone