XML Store issue

first time trying the xmlstore and having issues.

Can someone tell me what is wrong with my store?

Code:

Ext.define('app.store.MyFeedStoreXML', {    extend: 'Ext.data.Store',


    requires: [
        'app.model.MyFeed',
        'Ext.data.proxy.JsonP',
        'Ext.data.reader.Xml'
    ],


    config: {
        autoLoad: true,
        model: 'app.model.MyFeed',
        pageSize: 30,
        storeId: 'MyFeedStoreXML',
        proxy: {
            type: 'jsonp',
            url: 'http://ift.tt/1i4RpkW',
            reader: {
                type: 'xml',
                rootProperty: 'channel',
                record: 'item'
            }
        }
    }
});

trying to get the feed from the this url

http://ift.tt/1hYjlwF