Inherited methods doesn't work on 1.2?

Hello, I'm trying Rails 1.2 (edge-rails), and having a method in
ApplicationController it isn't visible by
another controller, why?

class ApplicationController < ActionController::Base
  def set_charset
    str_type = request.xhr? ? "javascript" : "html"
    @headers["Content-Type"] = "text/#{str_type}; charset=ISO-8859-1"

class BackupsController < ApplicationController
  after_filter :set_charset

  def index
    render :action => 'list'

  def list
    @backup_pages, @backups = paginate :backups, :per_page => 10

The error:

NoMethodError in BackupsController#list
undefined method `set_charset' for #<BackupsController:0xb772a74c>

What's happening?!!!!

I've tested the same in 1.1.6 and it works fine. Well I've already
tested it in another applications, but
I copied the files from one project to another to check it....

May be the way I configured the project to use Rails 1.2?