sessions - active record store

Question -
I'm using acts_as_authenticated and would like to store sessions in
ActiveRecord.
I've done the correct call in config/environment.rb
Still no sessions are being recorded in AR.

In looking through the code of AAA I see in authenticated_system.rb
there is this call:

module AuthenticatedSystem
  protected
    # Returns true or false if the user is logged in.
    # Preloads @current_user with the user model if they're logged in.
    def logged_in?
      (@current_user ||= session[:user] ?
User.find_by_id(session[:user]) : :false).is_a?(User)
    end

    # Accesses the current user from the session.
    def current_user
      @current_user if logged_in?
    end

    # Store the given user in the session.
    def current_user=(new_user)
      session[:user] = (new_user.nil? || new_user.is_a?(Symbol)) ? nil
: new_user.id
      @current_user = new_user
    end

Shouldn't the def current_user set the user id in an active record session ?

TIA
Stuart

Thought I had restarted server before posting but did it again.
Sessions now working.
Sorry
Stuart