Plugin Development in Rails 1.2.2

I am following the Rails Cookbook and working through the "Extending
Active Record with acts_as" recipe.

I created the migration, model and the plugins. The init.rb and the
acts_as_dictionary.rb is with the sample code. When I do the script/
console, I get:

03:14:11:~/work/railscb/dict > script/console
Loading development environment.
/usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.1/lib/
active_support/dependencies.rb:263:in
`load_missing_constant':NameError: uninitialized constant
ActiveRecord::Acts::Dictionary

Why is it blowing up? Is it because the latest Rails does not allow
polluting the Acts namespace? TIA.