generate model error

I'm new on rails, and I encountered a problem when I am doing a
tutorial: that's a simple application without a database.

First "rails simple_app"
And modify "enviroment.rb"

  # Skip frameworks you're not going to use. To use Rails without a
  # you must remove the Active Record framework.
  config.frameworks -= [ :active_record, :active_resource,
:action_mailer ]

However, after that when I execute the command "ruby script/generate
model Item" there will be an error raised:
uninitialized constant ModelGenerator::ActiveRecord

Anyone knows the origin of the problem, and how to solve it

BTW: I am using rails 2.3.4 and ruby 1.8.7

I may be wrong ( I often am ) but I would guess that the Model
generator assumes that you are using ActiveRecord. It does generate
migrations after all.

Unless you really want to use Rails without a db then I would give it
one. You do not have to do anything with it in your first forays,
just make it available to keep Rails happy.