Rails 3.2.12 - HTML5 - Offline cache manifest , running but no page rendered

Where am I wrong ? I should have missed some important trick… after
compiling assets, and running my app in local production mode ,

going to root url =>.I just get a white page …

the console : start th render the home page then get all the cache … ,
and no page rendered …

Listening on 0.0.0.0:3000, CTRL+C to stop
Started GET “/” for 127.0.0.1 at 2013-02-12 19:09:46 +0100
Processing by WelcomeController#index as HTML
… more …
Rendered welcome/index.html.haml within layouts/application (438.3ms)
Completed 200 OK in 3700ms (Views: 539.7ms | ActiveRecord: 101.8ms)
Started GET “/fr/application.manifest” for 127.0.0.1 at 2013-02-12
19:09:51 +0100
CACHE MANIFEST

b674b99ed2e29478bf9b8887fd1448dcd5755e2b2f8882a9abf2030d70ae5ae5

404.html
422.html
500.html
offline.html
assets/application-cb5548d93b80852ceb169309f728eb75.js
… more assets …

In my application.html.haml

%html{:lang => “en”, :manifest => manifest_path }

In my routes.rb

Rack::Offline.configure do
cache “assets/application.js”
cache “assets/application.css”
network “/”
end
match “/application.manifest” => Rails::Offline, :as => :manifest

In my mimes_types.rb

Mime::Type.register “text/cache-manifest”, :manifest