Ext.Loader.setConfig({
    enabled: true,
    disableCaching: false,
    paths: {
        GeoExt: "../../src/GeoExt",
        Ext: "http://cdn.sencha.io/ext-4.1.0-gpl/src"
    }
});

@@ -147,24 +147,25 @@
 cha.
-io
+com
 /ext
--4.1.0-gpl
+/gpl/4.2.1
 /src

Upgrade loader to point to Ext 4.2.1