Ember.js bug with nested models

client.hbs

<h1>{{name}}</h1>

Client's name shows up fine. But campaigns don't :(

<br />

{{content.campaigns}} => <DS.ManyArray:ember374>

<br />

{{#each content.campaigns}}
  No donut. Nothing shows up here. Using debugger, I can't
  access firstObject nor anything. It's as if campaigns was
  simply empty.
{{/each}}

console.md

ember.js

// models
Admin.Client = DS.Model.extend({
  name: DS.attr('string'),
  campaigns: DS.hasMany('campaign')
});

Admin.Campaign = DS.Model.extend({
  title: DS.attr('string'),
  client: DS.belongsTo('client')
});

// router
Admin.ClientRoute = Ember.Route.extend({
  // Without overriding this, Ember errors out on 1.0.0
  model: function(params) {
    return this.store.find('client', params.client_id);
  }
});

load.json

{
  "campaigns": [{
    "id":8,
    "title":"aaaa"
  }],
  "client": {
    "id":18,
    "name":"bebebe",
    "campaign_ids":[8]    
  }
}