Ошибка маршрутизации Rails с помощью response_with при создании вложенного ресурса

У меня возникла следующая проблема с простым приложением Rails 3, которое я создаю. Это сводит меня с ума.

Моя модель:

class Vehicle < ActiveRecord::Base
    has_many :vehicle_pictures, :dependent => :destroy
def

class VehiclePicture < ActiveRecord::Base
   belongs_to :vehicle
end

My routes.rb:

MyApp::Application.routes.draw do
    resources :vehicles do
        resources :pictures, :controller => :vehicle_pictures
    end
end

Мои rake routes вывод:

    vehicle_pictures GET    /vehicles/:vehicle_id/pictures(.:format)            {:action=>"index", :controller=>"vehicle_pictures"}
                     POST   /vehicles/:vehicle_id/pictures(.:format)            {:action=>"create", :controller=>"vehicle_pictures"}
 new_vehicle_picture GET    /vehicles/:vehicle_id/pictures/new(.:format)        {:action=>"new", :controller=>"vehicle_pictures"
edit_vehicle_picture GET    /vehicles/:vehicle_id/pictures/:id/edit(.:format)   {:action=>"edit", :controller=>"vehicle_pictures"}
     vehicle_picture GET    /vehicles/:vehicle_id/pictures/:id(.:format)        {:action=>"show", :controller=>"vehicle_pictures"}
                     PUT    /vehicles/:vehicle_id/pictures/:id(.:format)        {:action=>"update", :controller=>"vehicle_pictures"}
                     DELETE /vehicles/:vehicle_id/pictures/:id(.:format)        {:action=>"destroy", :controller=>"vehicle_pictures"}

My vehicle_pictures_controller.rb:

class VehiclePicturesController < ApplicationController

  before_filter :find_vehicle

  respond_to :html, :json, :xml

  private
  def find_vehicle
    @vehicle = Vehicle.find(params[:vehicle_id])
  end

  public

  # GET /vehicle/:id/pictures
  def index
    @pictures = @vehicle.vehicle_pictures

    respond_with(@pictures)
  end

  # GET /vehicle/:vehicle_id/pictures/new
  def new
    @picture = VehiclePicture.new
    @picture.vehicle = @vehicle

    respond_with(@picture)
  end

  # POST /vehicle/:vehicle_id/pictures
  def create
    @picture = @vehicle.vehicle_pictures.build(params[:vehicle_picture])

    flash[:notice] =  'Vehicle picture was successfully created.' if @picture.save

    respond_with(@picture)
  end

  # GET /vehicle/:vehicle_id/pictures/:id
  def show
    @picture = @vehicle.vehicle_pictures.find(params[:id])
    respond_with(@picture)
  end

  # DELETE /vehicle/:vehicle_id/pictures/:id
  def destroy
    @picture = @vehicle.vehicle_pictures.find(params[:id])
    @picture.destroy
    respond_with(@picture)
  end

end

Когда я публикую новое изображение автомобиля, метод create вызывается, как и ожидалось, но я получаю следующую ошибку:

No route matches {:controller=>"vehicle_pictures", :action=>"show", :vehicle_id=>#<VehiclePicture id: 24, created_at: "2011-04-08 15:07:53", updated_at: "2011-04-08 15:07:53", picture: nil, description: "", vehicle_id: 1>}

Если я изменю response_with на response_with (@picture,: location => vehicle_picture_url (@ vehicle.id, @ picture.id)) все работает.

Но насколько я понимаю, мне не следовало этого делать. Что я делаю не так?