Oops, don't omit the session_key since it's used as the cookie name.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6199 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

railties/environments/environment.rb

@@ -43,7 +43,10 @@
 
   # Your secret key for verifying cookie session data integrity.
   # If you change this key, all old sessions will become invalid!
-  config.action_controller.session = { :secret => '<%= CGI::Session.generate_unique_id(app_name) %>' }
+  config.action_controller.session = {
+    :session_key => '_<%= app_name %>_session',
+    :secret => '<%= CGI::Session.generate_unique_id(app_name) %>'
+  }
 
   # See Rails::Configuration for more options
 end