Gem install login_generator

I am trying to install a gem into my Dreamhost account:
http://wiki.dreamhost.com/index.php/Ruby_on_Rails#Using_gems_installed_in_your_home_directory

But it doesn’t work. I don’t quite understand the error message:

pico$ gem update --source http://gems.rubyonrails.com
Upgrading installed gems…
Updating Gem source index for: http://gems.rubyonrails.com
Gems: [] updated
pico$ gem install login_generator
Attempting local installation of ‘login_generator’
Local gem file not found: login_generator*.gem
Attempting remote installation of ‘login_generator’
/usr/local/lib/site_ruby/1.8/rubygems.rb:194:in report_activate_error': Could not find RubyGem sources (> 0.0.0) (Gem::LoadError) from /usr/local/lib/site_ruby/1.8/rubygems.rb:136:in activate’
from /usr/local/lib/site_ruby/1.8/rubygems.rb:37:in
require_gem_with_options' from /usr/local/lib/site_ruby/1.8/rubygems.rb:31:in require_gem’
from
/usr/local/lib/site_ruby/1.8/rubygems/remote_installer.rb:403:in
sources' from /usr/local/lib/site_ruby/1.8/rubygems/remote_installer.rb:413:in source_index_hash’
from
/usr/local/lib/site_ruby/1.8/rubygems/remote_installer.rb:377:in
install' from /usr/local/lib/site_ruby/1.8/rubygems/gem_commands.rb:179:in execute’
from
/usr/local/lib/site_ruby/1.8/rubygems/gem_commands.rb:137:in each' from /usr/local/lib/site_ruby/1.8/rubygems/gem_commands.rb:137:in execute’
from /usr/local/lib/site_ruby/1.8/rubygems/command.rb:49:in
invoke' from /usr/local/lib/site_ruby/1.8/rubygems/cmd_manager.rb:92:in process_args’
from /usr/local/lib/site_ruby/1.8/rubygems/cmd_manager.rb:65:in
run' from /usr/local/lib/site_ruby/1.8/rubygems/gem_runner.rb:9:in run’
from /usr/bin/gem:17