Rails 3 getting wrong mocked models with Rspec, Nested Resources and inherited_resources

Question

I'm trying to test a nested controller with Rspec and mocked models but i'm getting these errors:

Failure/Error: it { assigns[:store].should equal(mock_store) } 
   expected #<Store:2198414660> => #<Store:0x83092544 @name="Store_1008">
        got #<User:2198383140> => #<User:0x8308aa24 @name="User_1009">

and i can't find why this is happening.

routes.rb

namespace :api do
  namespace :v1 do
    devise_for :users, :controllers => { :sessions => "devise/sessions", 
                                         :passwords => "devise/passwords", 
                                         :registrations => "devise/registrations" }
    resources :categories, :only => [ :index, :show ]
    resources :users, :only => [ :index, :show ] do
      resources :stores
    end

    resources :stores do
      resources :products
    end

    resources :products
  end
end

app/controllers/api/v1/stores_controller.rb

class Api::V1::StoresController < Api::ApiController
  belongs_to :user
  actions :all
end

app/controllers/api/api_controller.rb

class Api::ApiController < InheritedResources::Base
  respond_to :json
end

My spec/controllers/api/v1/stores_controller_spec.rb -> http://www.pastie.org/2118818 throws me these strange errors -> http://www.pastie.org/2118825.

Why do i always get the mocked User instead the Store.

If I remove the belongs_to :user line from app/controllers/api/v1/stores_controller.rb all my test pass, but i'm interested in testing "users/:user_id/stores/*" routes.

How can i test them correctly, and why i'm getting a Mocked User instead the Store.

I'm using

* inherited_resources (1.2.2)
* rails (3.0.7)
* rspec (2.5.0)
* rspec-core (2.5.2)
* rspec-expectations (2.5.0)
* rspec-mocks (2.5.0)
* rspec-rails (2.5.0)

Thanks for your time.