I've builded a app with symfony2 the app expose an REST Api.

now i build a simple client for consuming

app.coffee -> app.js

App = Em.Application.create
    ready: ->
        @.entradas.load()
    Entrada: Em.Object.extend()
    entradas: Em.ArrayController.create
        content: []
        load: ->
            url = 'http://localhost/api/1/entrada'
            me = @
            $.ajax(
                url: url,
                method: 'GET',
                success: (data) ->
                    me.set('content', [])
                    for entrada in data.data.objects
                        me.pushObject DBPlus.Entrada.create(entrada)
            )

MyBundle:Home:index.html.twig

<script type="text/x-handlebars" src="{{ asset('js/templates/entradas.hbs') }}"></script>
<script src="{{ asset('js/libs/jquery-1.7.2.min.js') }}"></script>
<script src="{{ asset('js/libs/handlebars-1.0.0.beta.6.js') }}"></script>
<script src="{{ asset('js/libs/ember-1.0.pre.min.js') }}"></script>
<script src="{{ asset('js/app.js') }}"></script>

the problem here is when i run on dev enviroment and link the template like <script type="text/x-handlebars" src="{{...}}"> the app dont work, nothing show but works fine over prod enviroment.

he only way that works on dev enviroment is inline template

MyBundle:Home:index.html.twig

<script type="text/x-handlebars">
    {% raw %}
    <ul class="entradas">
      {{#each App.entradas}}
        <li class="entrada">{{nombre}}</li>
      {{/each}}
    </ul>
    {% endraw %}
</script>

can explain why this behavoir?

Note: I disabled the debug profiler toolbar, and nothing