Redmine

I'm running Redmine with two environments, production and development. When I try to log in or log out on production, everything is fine. When I do the same on development instance, I get

ArgumentError in AccountController#logout

A copy of ApplicationController has been removed from the module tree but is still active!

/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:414:in `load_missing_constant'
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:96:in `const_missing'
/var/lib/redmine.stable/app/controllers/application_controller.rb:54:in `user_setup'@

I'm running 0.9-stable-r3898.

Here's the output from RAILS_ENV=development script/about:

/usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb:119:Warning: Gem::Dependency#version_requirements is deprecated and will be removed on or after August 2010.  Use #requirement
About your application's environment
Ruby version              1.8.7 (i686-linux)
RubyGems version          1.3.6
Rack version              1.0
Rails version             2.3.5
Active Record version     2.3.5
Active Resource version   2.3.5
Action Mailer version     2.3.5
Active Support version    2.3.5
Application root          /var/lib/redmine.stable
Environment               development
Database adapter          mysql
Database schema version   20100313171051

About your Redmine plugins
Redmine Bugcloud plugin            0.0.2.1
Scrumdashboard plugin              1.2
Redmine Backlogs plugin            0.0.1
Redmine Attach Screenshot plugin   0.0.3