I've exactly the same problem from this Question. However I'm using Sencha Touch 2 and I don't know how to actually use this custom store. I define my REST proxies inside the model classes. How would I access/use this custom proxy?
proxy: {
    type: 'rest',
    url: 'http://someUrl', 
    reader: {
        type: 'json',
    }
}
 
     
    