Active_rbac doesn't understand before_filter

I’ve moved an application onto the production server, and found that
when I run it under the production environment active_rbac doesn’t work
(it’s fine under the development environment). I find this in the logs
when trying to view a protected page:

NoMethodError (undefined method `before_filter’ for
ActiveRbac::ComponentController:Class):
/app/controllers/active_rbac/component_controller.rb:2
…lots more stuff…

The offending code is:

class ActiveRbac::ComponentController
before_filter :protect_with_active_rbac

    protected

            def protect_with_active_rbac
                    # only protect certain controllers
                    return true if [ActiveRbac::LoginController,

ActiveRbac::RegistrationController,
ActiveRbac::MyAccountController].include?(self.class)

                    # protect!
                    if !session[:rbac_user_id].nil? and

User.find_by_id(session[:rbac_user_id]).has_role?(“Admin”)
return true
else
flash[:notice] = “Please log in to
access this page.”
redirect_to “/login”
return false
end
end
end

Can anyone suggest where I might begin to look for the cause of this
error?