Redmine

I want to change my redmine to use memcached.
I do like http://www.redmineblog.com/page2 and redmine run faster than before.
But when I want to go to "Administration -> Settings" or "My Account" I get an "Redmine error 500".

config/additional_environment.rb

# config/additional_environment.rb
#
config.gem 'memcached' # For other hosts
# config.gem 'memcached-northscale', :lib => 'memcached' # For Heroku.com
require 'memcached'
config.cache_store = :mem_cache_store, ::Memcached::Rails.new('127.0.0.1:1121')

log/production.log

ActionView::Template::Error (Key {"i18n/languages_options"=>"127.0.0.1:1121:8"}):
    3: <div class="box tabular settings">
    4: <p><%= setting_select :ui_theme, Redmine::Themes.themes.collect {|t| [t.name, t.id]}, :blank => :label_default, :label => :label_theme %></p>
    5:
    6: <p><%= setting_select :default_language, lang_options_for_select(false) %></p>
    7:
    8: <p><%= setting_select :start_of_week, [[day_name(1),'1'], [day_name(6),'6'], [day_name(7),'7']], :blank => :label_language_based %></p>
    9: <% locale = User.current.language.blank? ? ::I18n.locale : User.current.language %>
  lib/redmine/i18n.rb:95:in `languages_options'
  app/helpers/application_helper.rb:975:in `lang_options_for_select'
  app/views/settings/_display.html.erb:6:in `block in _app_views_settings__display_html_erb___1813701505727690650_36871100'
  app/views/settings/_display.html.erb:1:in `_app_views_settings__display_html_erb___1813701505727690650_36871100'
  app/views/common/_tabs.html.erb:24:in `block in _app_views_common__tabs_html_erb___2743497495253920682_47075300'
  app/views/common/_tabs.html.erb:23:in `each'
  app/views/common/_tabs.html.erb:23:in `_app_views_common__tabs_html_erb___2743497495253920682_47075300'
  app/helpers/application_helper.rb:263:in `render_tabs'
  app/views/settings/edit.html.erb:3:in `_app_views_settings_edit_html_erb__3216536329719411937_46993280'
  app/controllers/settings_controller.rb:26:in `index'

Apache error Log

cache error: Key {"https://nbg-dev03/redmine/settings?"=>"127.0.0.1:1121:8"}
/var/lib/gems/1.9.1/gems/memcached-1.5.0/lib/memcached/memcached.rb:630:in `reraise'
/var/lib/gems/1.9.1/gems/memcached-1.5.0/lib/memcached/memcached.rb:608:in `check_return_code'
/var/lib/gems/1.9.1/gems/memcached-1.5.0/lib/memcached/memcached.rb:517:in `get'
/var/lib/gems/1.9.1/gems/memcached-1.5.0/lib/memcached/rails.rb:50:in `get'
/var/lib/gems/1.9.1/gems/activesupport-3.2.11/lib/active_support/cache/mem_cache_store.rb:130:in `read_entry'
/var/lib/gems/1.9.1/gems/activesupport-3.2.11/lib/active_support/cache/strategy/local_cache.rb:134:in `read_entry'
/var/lib/gems/1.9.1/gems/activesupport-3.2.11/lib/active_support/cache/mem_cache_store.rb:187:in `read_entry'
/var/lib/gems/1.9.1/gems/activesupport-3.2.11/lib/active_support/cache.rb:316:in `block in read'
/var/lib/gems/1.9.1/gems/activesupport-3.2.11/lib/active_support/cache.rb:520:in `instrument'
/var/lib/gems/1.9.1/gems/activesupport-3.2.11/lib/active_support/cache.rb:315:in `read'
/var/lib/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/http/rack_cache.rb:17:in `read'
/var/lib/gems/1.9.1/gems/rack-cache-1.2/lib/rack/cache/metastore.rb:30:in `lookup'
/var/lib/gems/1.9.1/gems/rack-cache-1.2/lib/rack/cache/context.rb:169:in `lookup'
/var/lib/gems/1.9.1/gems/rack-cache-1.2/lib/rack/cache/context.rb:66:in `call!'
/var/lib/gems/1.9.1/gems/rack-cache-1.2/lib/rack/cache/context.rb:51:in `call'
/var/lib/gems/1.9.1/gems/railties-3.2.11/lib/rails/engine.rb:479:in `call'
/var/lib/gems/1.9.1/gems/railties-3.2.11/lib/rails/application.rb:223:in `call'
/var/lib/gems/1.9.1/gems/railties-3.2.11/lib/rails/railtie/configurable.rb:30:in `method_missing'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/rack/request_handler.rb:96:in `process_request'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/abstract_request_handler.rb:516:in `accept_and_process_next_request'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/abstract_request_handler.rb:274:in `main_loop'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/classic_rails/application_spawner.rb:321:in `start_request_handler'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/classic_rails/application_spawner.rb:275:in `block in handle_spawn_application'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/utils.rb:470:in `safe_fork'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/classic_rails/application_spawner.rb:270:in `handle_spawn_application'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server.rb:357:in `server_main_loop'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server.rb:206:in `start_synchronously'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server.rb:180:in `start'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/classic_rails/application_spawner.rb:149:in `start'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/spawn_manager.rb:219:in `block (2 levels) in spawn_rails_application'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server_collection.rb:132:in `lookup_or_add'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/spawn_manager.rb:214:in `block in spawn_rails_application'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server_collection.rb:82:in `block in synchronize'
<internal:prelude>:10:in `synchronize'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server_collection.rb:79:in `synchronize'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/spawn_manager.rb:213:in `spawn_rails_application'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/spawn_manager.rb:132:in `spawn_application'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/spawn_manager.rb:275:in `handle_spawn_application'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server.rb:357:in `server_main_loop'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/lib/phusion_passenger/abstract_server.rb:206:in `start_synchronously'
/var/lib/gems/1.9.1/gems/passenger-3.0.17/helper-scripts/passenger-spawn-server:99:in `<main>'

Ruby-Version:

Ruby version              1.9.3 (x86_64-linux)
RubyGems version          1.8.11
Rack version              1.4
Rails version             3.2.11
Active Record version     3.2.11
Action Pack version       3.2.11
Active Resource version   3.2.11
Action Mailer version     3.2.11
Active Support version    3.2.11
Middleware                Rack::Cache, ActionDispatch::Static, Rack::Lock, #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x000000036076a8>, Rack::Runtime, Rack::MethodOverride, ActionDispatch::RequestId, Rails::Rack::Logger, ActionDispatch::ShowExceptions, ActionDispatch::DebugExceptions, ActionDispatch::RemoteIp, ActionDispatch::Callbacks, ActiveRecord::ConnectionAdapters::ConnectionManagement, ActiveRecord::QueryCache, ActionDispatch::Cookies, ActionDispatch::Session::CookieStore, ActionDispatch::Flash, ActionDispatch::ParamsParser, ActionDispatch::Head, Rack::ConditionalGet, Rack::ETag, ActionDispatch::BestStandardsSupport, OpenIdAuthentication
Application root          /var/software/redmine-2.2.2
Environment               production
Database adapter          mysql2
Database schema version   20121026003537

Redmine-Version

Environment:
  Redmine version                          2.2.2.stable
  Ruby version                             1.9.3 (x86_64-linux)
  Rails version                            3.2.11
  Environment                              production
  Database adapter                         Mysql2
Redmine plugins:
  redmine_extended_spent_time              0.0.3
  redmine_favourite_projects               0.6
  redmine_hudson                           1.0.8
  redmine_issue_control_panel              0.3.0
  redmine_lightbox                         0.0.1
  redmine_logs                             0.0.5
  redmine_monitoring_controlling           0.1.1
  redmine_mylyn_connector                  2.8.2.stable
  redmine_wiki_extensions                  0.6.1
  timesheet_plugin                         0.6.0