express + i18n-node + handlebars and avoid concurrency issues

i18n-express-hbs-app.js

// require modules
var express = require('express'),
    i18n = require('i18n'),
    hbs = require('hbs'),
    app = module.exports = express();

i18n.configure({
  locales: ['en', 'fr'],
  cookie: 'locale',
  directory: "" + __dirname + "/locales"
});

app.configure(function () {
  // setup hbs
  app.set('views', "" + __dirname + "/views");
  app.set('view engine', 'hbs');
  app.engine('hbs', hbs.__express);

  // you'll need cookies
  app.use(express.cookieParser());

  // init i18n module for this loop
  app.use(i18n.init);

});

// register hbs helpers in res.locals' context which provides this.locale
hbs.registerHelper('__', function () {
  return i18n.__.apply(this, arguments);
});
hbs.registerHelper('__n', function () {
  return i18n.__n.apply(this, arguments);
});

// serving homepage
app.get('/', function (req, res) {
  res.render('index');
});

// startup
app.listen(3000);

index.hbs

<span id="text">{{{__ "text to test"}}}</span>
<br>
<span id="onecat">{{{__n "%d cat" "%d cats" 1}}}</span>
<br>
<span id="twocats">{{{__n "%d cat" "%d cats" 2}}}</span>