Cache_sweeper undefined for controllers

Any clues on why I’m getting cache_sweeper undefined to any controller
on Rails 2.1?

NoMethodError (undefined method cache_sweeper' for CommentsController:Class): /app/controllers/comments_controller.rb:5 /vendor/rails/activesupport/lib/active_support/dependencies.rb:216:inload_without_new_constant_marking’
/vendor/rails/activesupport/lib/active_support/dependencies.rb:216:in
load_file' /vendor/rails/activesupport/lib/active_support/dependencies.rb:355:innew_constants_in’
/vendor/rails/activesupport/lib/active_support/dependencies.rb:215:in
load_file' /vendor/rails/activesupport/lib/active_support/dependencies.rb:96:inrequire_or_load’
/vendor/rails/activesupport/lib/active_support/dependencies.rb:261:in
load_missing_constant' /vendor/rails/activesupport/lib/active_support/dependencies.rb:468:inconst_missing_not_from_s3_library’
/opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/aws-s3-0.5.1/lib/aws/s3/extensions.rb:174:in
const_missing' /vendor/rails/activesupport/lib/active_support/dependencies.rb:480:inconst_missing’
/vendor/rails/activesupport/lib/active_support/inflector.rb:285:in
constantize' /vendor/rails/activesupport/lib/active_support/inflector.rb:284:ineach’
/vendor/rails/activesupport/lib/active_support/inflector.rb:284:in
constantize' /vendor/rails/activesupport/lib/active_support/core_ext/string/inflections.rb:143:inconstantize’
/vendor/rails/actionpack/lib/action_controller/routing/route_set.rb:387:in
recognize' /vendor/rails/actionpack/lib/action_controller/dispatcher.rb:148:inhandle_request’
/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:107:in
dispatch' /vendor/rails/actionpack/lib/action_controller/dispatcher.rb:104:insynchronize’
/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:104:in
dispatch' /vendor/rails/actionpack/lib/action_controller/dispatcher.rb:120:indispatch_cgi’
/vendor/rails/actionpack/lib/action_controller/dispatcher.rb:35:in
dispatch' /opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/../lib/mongrel/rails.rb:76:inprocess’
/opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/…/lib/mongrel/rails.rb:74:in
synchronize' /opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/../lib/mongrel/rails.rb:74:inprocess’
/opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:159:in
process_client' /opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:158:ineach’
/opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:158:in
process_client' /opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:inrun’
/opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in
initialize' /opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:innew’
/opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:285:in
run' /opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:ininitialize’
/opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:in
new' /opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel.rb:268:inrun’
/opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel/configurator.rb:282:in
run' /opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel/configurator.rb:281:ineach’
/opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel/configurator.rb:281:in
run' /opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:128:inrun’
/opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/lib/mongrel/command.rb:212:in
run' /opt/ruby-enterprise-1.8.6-20080810/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:281 /vendor/rails/activesupport/lib/active_support/dependencies.rb:503:inload’
/vendor/rails/activesupport/lib/active_support/dependencies.rb:503:in
load' /vendor/rails/activesupport/lib/active_support/dependencies.rb:355:innew_constants_in’
/vendor/rails/activesupport/lib/active_support/dependencies.rb:503:in
load' /vendor/rails/railties/lib/commands/servers/mongrel.rb:64 /opt/ruby-enterprise-1.8.6-20080810/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:ingem_original_require’
/opt/ruby-enterprise-1.8.6-20080810/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
require' /vendor/rails/activesupport/lib/active_support/dependencies.rb:510:inrequire’
/vendor/rails/activesupport/lib/active_support/dependencies.rb:355:in
new_constants_in' /vendor/rails/activesupport/lib/active_support/dependencies.rb:510:inrequire’
/vendor/rails/railties/lib/commands/server.rb:39
/opt/ruby-enterprise-1.8.6-20080810/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
gem_original_require' /opt/ruby-enterprise-1.8.6-20080810/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:inrequire’
script/server:3

-Fabio.