Rails—部署中的失败路由

我有一个应用程序在routes文件中包含以下内容:

  namespace "admin" do 
    # ADMINISTRATIVE ROUTES ONLY 
    root :to => 'home#index' 
    resources :comments do 
      member do 
        get :approve 
        get :reject 
      end 
    end 
    resources :users do 
      member do 
        get :block 
        get :unblock 
      end 
    end 
  end 

当浏览到本地的/admin时,我会看到相应的页面。 在heroku版本的同一个URL上,我得到一个404

ActionController::RoutingError (wrong constant name Admin/ 
homeController): 
/disk1/home/slugs/196384_c95a9e3_4463/mnt/.bundle/gems/gems/ 
activesupport-3.0.0.beta4/lib/active_support/inflector/methods.rb: 
103:in `const_defined?'

有什么想法吗?