SharePoint Remote App access SP user error: RE_DomainDoesNotMatch

I am building a provider hosted App for SharePoint using cross domain JavaScript library. This is a single page application based on Backbone.js. The code calls App web (not host web) using cross domain JavaScript library using object model or REST API.

The following code works locally (when remote App is hosted on localhost port within VS.NET 2012) but when I changed App manifest to point to a windows azure site (after I successfully published my remote web), I encountered an error access App web user info - believe trying to access list info will fail which follows accessing the user info.

var hostweburl = Utils.getHostWebUrl(document);
var appweburl = Utils.getAppWebUrl(document);
var scriptbase = hostweburl + "/_layouts/15/";

$.getScript(scriptbase + "SP.Runtime.js",
  function () {
    $.getScript(scriptbase + "SP.js", function () {
       $.getScript(scriptbase + "SP.RequestExecutor.js", NetworkStore.crossDomainSharePointReady);
       });
});
...
crossDomainSharePointReady: function () {
  var appweburl = Utils.getAppWebUrl(document);
  var context = new SP.ClientContext(appweburl);
  var factory =
            new SP.ProxyWebRequestExecutorFactory(appweburl);
  context.set_webRequestExecutorFactory(factory);

  NetworkStore.loadUser(context);
},
loadUser: function (context) {

  var web = context.get_web();
  this.user = web.get_currentUser();
  context.load(this.user);
  context.executeQueryAsync(this.onGetUserNameSuccess, this.onGetUserNameFail);
},
onGetUserNameSuccess: function () {
   this.currentLoginName = NetworkStore.user.get_loginName();
},

onGetUserNameFail: function (sender, args) {
   console.log('Failed to get user name: ' + args.get_message());
},

The erorr I got is: Failed to get user name: RE_DomainDoesNotMatch

I am wondering which domain needs to match which.