Session being lost before TwitterOauth callback

I'm building something like a multi-twitter-feed-manager, using the TwitterOauth plugin to handle authorization with Twitter. Before redirecting to Twitter, I add some data to the session. When Twitter redirects to the callback, the session is empty. Can anyone explain this?

Here's the controller.

class TwitterAuthorizationsController < ApplicationController   def new     @authorization = TwitterAuthorization.new     @authorization.request     @authorization.prepare_session session

    #this correctly prints out the session     puts "TwitterAuthorizationsController#new session # {session.to_json}"

    redirect_to @authorization.url   end

  def callback     #and here it's empty     puts "TwitterAuthorizationsController#callback session # {session.to_json}"

    @authorization = TwitterAuthorization.new     @authorization.authorize session

    @authorization.save   end end

And here's the model:

class TwitterAuthorization < ActiveRecord::Base   has_many :twitter_authentications

  def initialize     @client = TwitterOAuth::Client.new(:consumer_key => '**********************',:consumer_secret => '******************')   end

  def request     @request_token = @client.request_token(:oauth_callback => 'http:// 0.0.0.0:3000/oauth_callback')   end

  def authorize session     puts "DEBUG session #{session.to_json}"     @access_token = @client.authorize(                                       session[:request_token],                                       session[:request_token_secret],                                       :oauth_verifier => params [:oauth_verifier])     if @client.authorized?       access_token = @access_token.token       secret_token = @access_token.secret     end   end

  def prepare_session session     session[:request_token] = @request_token.token     session[:request_token_secret] = @request_token.secret   end

  def url     @request_token.authorize_url   end end

Thanks!

-Andrew