I could not fix this in Rails 3.2.12, maybe I am missing something.
config/routes.rb
get \"home/index\" root :to => \"home#index\
Rails requires the file name to match the class name. Therefore you should rename app/controllers/authentication_controller.rb to app/controllers/authentications_controller.rb.
app/controllers/authentication_controller.rb
app/controllers/authentications_controller.rb