Why won't formtastic reflect attr_accessible in the model (Ruby on Rails)

Question

Why won't rails reflect attr_accessible in my model?

class User < ActiveRecord::Base
  acts_as_authentic
  attr_accessible :name, :email, :phone, :password, :password_confirmation
  ...

When I use formtastic or outprints the model xml, both reveals all the model fields like admin:boolean, password-encrypted:string and so on.

Rails 2.3.8