Autoload Path and Nest

I have tow files hoge.rb and baz.rb.

app/models/hoge.rb

class Hoge
  class Fuga
    Baz.new
  end
end

app/models/hoge/baz.rb

class Baz
end

I have added the custom models to load path as follows.

config/environment.rb

config.autoload_paths += %W( #{RAILS_ROOT}/app/models/hoge )

Hoge::Fuga.new is LoadError: Expected in development mode as follows.

% script/console
Loading development environment (Rails 2.3.11)
>> Hoge::Fuga.new
LoadError: Expected /home/admin/apps/ad_counter/hoge/app/models/hoge/baz.rb to define Hoge::Baz
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:452:in `load_missing_constant'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:122:in `const_missing'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:463:in `load_missing_constant'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:122:in `const_missing'
        from /home/admin/apps/ad_counter/hoge/app/models/hoge.rb:3
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:406:in `load_without_new_constant_marking'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:406:in `load_file'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:547:in `new_constants_in'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:405:in `load_file'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:285:in `require_or_load'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:451:in `load_missing_constant'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:106:in `const_missing'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:118:in `const_missing'
        from (irb):1

Next is production mode as follows.

% script/console production
Loading production environment (Rails 2.3.11)
/usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:452:in `load_missing_constant': Expected /home/admin/apps/ad_counter/hoge/app/models/hoge/baz.rb to define Hoge::Baz (LoadError)
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:122:in `const_missing'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:463:in `load_missing_constant'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:122:in `const_missing'
        from /home/admin/apps/ad_counter/hoge/app/models/hoge.rb:3
        from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
        from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:184:in `require'
        from /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.11/lib/active_support/dependencies.rb:291:in `require_or_load'
         ... 18 levels...
        from /usr/local/lib/ruby/1.8/irb/init.rb:250:in `load_modules'
        from /usr/local/lib/ruby/1.8/irb/init.rb:21:in `setup'
        from /usr/local/lib/ruby/1.8/irb.rb:54:in `start'
        from /usr/local/bin/irb:13

raise is activesupport-2.3.11/lib/active_support/dependencies.rb L 452

452         raise LoadError, "Expected #{file_path} to define #{qualified_name}" unless uninherited_const_defined?(from_mod, const_name)


It's OK when baz.rb file in app/models derectory.

% script/console
Loading development environment (Rails 2.3.11)
>> Hoge::Fuga.new
=> #<Hoge::Fuga:0xb7686ed0>

I am on Ruby 1.8.6, Rails 2.3.11, CentOS 5.3.