If you get an 500 internal server error and see the following in the log file:
CGI::Session::CookieStore::CookieOverflow
Go ahead and use database session. It looks like the rails session only stores 4k of data. If you have a large form, it might not work.
uncomment this:
config.action_controller.session_store = :active_record_store
in environment.rb.
Restart the server and 