Uninitialized constant error with restful authentication

I’m trying to set up restful authentication with Rails 2.1.0 on Mac OS X
Leopard, and I had to comment out RAILS_GEM_VERSION in the environment
file to install the plugin from technoweenie. Now I’m trying to follow
along in a tuturial, and I’m stuck on this:

  1. $ ruby script/generate scaffold Role rolename:string

/Library/Ruby/Gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:492:in
const_missing': uninitialized constant User::Authentication (NameError) 3. from /Users/naijaguy/Sites/rails_apps/testauthapp/app/models/user.rb:4 4. from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:215:inload_without_new_constant_marking’
5. from
/Library/Ruby/Gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:215:in
load_file' 6. from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:354:innew_constants_in’
7. from
/Library/Ruby/Gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:214:in
load_file' 8. from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:95:inrequire_or_load’
9. from
/Library/Ruby/Gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:260:in
load_missing_constant' 10. from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.0/lib/active_support/dependencies.rb:467:inconst_missing’
11. … 28 levels…
12. from
/Library/Ruby/Gems/1.8/gems/rails-2.1.0/lib/commands/generate.rb:1
13. from /Library/Ruby/Site/1.8/rubygems/custom_require.rb:27:in
gem_original_require' 14. from /Library/Ruby/Site/1.8/rubygems/custom_require.rb:27:inrequire’
15. from script/generate:3

Was something (e.g. Authentication) not included when I downloaded the
plugin? I added this line to my ApplicationController:

include AuthenticatedSystem