How to test user features using Authlogic_RPX and Steak?

Question

I'm trying to test features of my Rails 3 app for which a user should be signed in.

I use authlogic_rpx for authenticating users through Facebook and Twitter, but I don't want to test that process. What I am looking for is to programmatically create a user session.

I tried to add this to my acceptance_helper.rb file:

require "authlogic/test_case"

Spec::Runner.configure do |config|
  config.include Authlogic::TestCase, :type => :acceptance
  config.before(:each, :type => :acceptance) do
    activate_authlogic
  end
end

And test like this:

scenario "Sign in" do
  user = Factory(:user)
  UserSession.create(user)

  visit root_path

  save_and_open_page
end

But then the @current_user variable looks empty. (I use it everywhere to see if the user has signed in.)

Any idea?

Kevin