Anybody good with Ruby on Rails need help!!

Hi I have started learning RoR recently and had like hundreds on hundreds of problems installing it on MAC.
Finally I have everything installed:
Ruby
Ruby Gems
Rails
Git
Heroku
Now I am following the following tutoria from chapter 2:
http://ruby.railstutorial.org/chapters/a-demo-app#top
And when it comes to the part to construct the data model it comes up with the following error:
Artful-Dodgers-iMac:~ mohammedshuheb$ cd ~/rails_projects
Artful-Dodgers-iMac:rails_projects mohammedshuheb$ cd demo_app
Artful-Dodgers-iMac:demo_app mohammedshuheb$ rails generate scaffold Users name:string email:string
/Users/mohammedshuheb/rails_projects/demo_app/config/application.rb:7: undefined method `groups' for Rails:Module (NoMethodError)
from /Library/Ruby/Gems/1.8/gems/railties-3.0.11/lib/rails/commands.rb:15:in `require'
from /Library/Ruby/Gems/1.8/gems/railties-3.0.11/lib/rails/commands.rb:15
from script/rails:6:in `require'
from script/rails:6
I used the command: rails generate scaffold Users name:string email:string to make the two fields name and email.
Anyone?
Need help
Thanks!!!

This post is from a long time ago, so I hope that you have your issue sorted out. I'm not familiar with the Mac environment, however posting on BHW for advice on programming is like asking birds how to swim, some can do it but their strength is flying (or internet marketing). My advice would be to hit up the IRC #rubyonrails channel and see what they have to say.

How did it end up for you?