Ruby on Rails install

[John Dangler]

I'm running Dapper 6.06LTS and am in the process of installing ruby and
rails.

I've been following the Dapper installation setup at
http://www.urbanpuddle.com/articles/2006/06/10/install-ruby-rails-on-ubuntu-dapper-drake

2 questions...

During this process (sudo ruby setup.rb)
I notice it says that it is removing 
Removing old RubyGems RDoc and ri...
and installing updated versions.
Should I pin those apps in Synaptic to avoid conflicts?

After that installation is complete, the next step says this:
sudo gem install rails --include-dependencies

And, this is what I get - 
Bulk updating Gem source index for: http://gems.rubyforge.org
ERROR:  While executing gem ... (Gem::GemNotFoundException)
    Could not find rails (> 0) in any repository

I'm a little confused at this point, since I thought that this process
would install rails...

What am I doing wrong?