FactoryGirl and protected attributes

user.rb

class User < ActiveRecord::Base
  # devise configuration info omitted

  # admin column is defined with :default => false

  attr_accessible :email, :password, :password_confirmation
end

user_factory-trait.rb

FactoryGirl.define do
  trait :admin do
    sequence(:email)        { |n| "admin#{n}@ticketee.com" }
    admin                   true
  end

  factory :user do
    sequence(:email)        { |n| "user#{n}@ticketee.com" }
    password                "password"
    password_confirmation   "password"
    confirmed_at            { Time.now() }

    factory :admin, :traits => [:admin]
  end
end

user_factory-two-factories.rb

# admin factory does not work!

FactoryGirl.define do
  factory :user do
    sequence(:email)        { |n| "user#{n}@ticketee.com" }
    password                "password"
    password_confirmation   "password"
    confirmed_at            { Time.now() }
  end

  factory :admin, :class => User do 
    sequence(:email)        { |n| "admin#{n}@ticketee.com" }
    password                "password"
    password_confirmation   "password"
    confirmed_at            { Time.now() }
    admin                    true
  end
end

@one = FactoryGirl.create(:admin)
# @one is created but @one.admin => false
@two = FactoryGirl.create(:user, :admin => true)
# @two is created and @two.admin => true