[Rails] Problems installing gems using rails

[Juan Pablo Romero]

Hello

I'm trying to use rubyonrails, but had some troubles:

First, there was an issue with gems (it did not finished the installation):

# gem install rails
Config file /root/.gemrc does not exist
Attempting local installation of 'rails'
Local gem file not found: rails*.gem
Attempting remote installation of 'rails'
Updating Gem source index for: http://gems.rubyforge.org
Install required dependency rake? [Yn]
Install required dependency activesupport? [Yn]
Install required dependency activerecord? [Yn]
Install required dependency actionpack? [Yn]
Install required dependency actionmailer? [Yn]
Install required dependency actionwebservice? [Yn]
Successfully installed rails, version 0.10.0
Installing RDoc documentation for rails-0.10.0...
Installing RDoc documentation for rake-0.4.15...
Installing RDoc documentation for activesupport-1.0.0...
Installing RDoc documentation for activerecord-1.7.0...
Installing RDoc documentation for actionpack-1.5.0...
ERROR:  While executing gem ... (NoMethodError)
    undefined method `find_module_named' for nil:NilClass
#


Nevertheless, I decided to proceed with rails. Tried to follow the 
tutorial at

http://manuals.rubyonrails.com/read/book/7

Everything went fine until I arrive to this code:

$ ruby script/generate model Prueba

      exists  app/controllers/
      exists  app/helpers/
      create  app/views/prueba
      exists  test/functional/
      create  app/controllers/prueba_controller.rb
undefined local variable or method `class_name' for 
#<Rails::Generator::Commands::Create:0x407b48a0>
$

¿What's going on here?


My system:

Mandrake 10.1 (updated from 10)
ruby 1.8.1

Thanks in advance

   Juan Pablo