sessions with custom handler

I have sessions working to a postgresql database. To test out what happens during a failure, I replaced the calls to _read and _write in the custom save handler to always return false. How can I tell if sessions are working correctly? session_start() always returns true. And, session_register() also always seems to return true (I thought it would return false as my _write handler was always returning false). -- albert chin (china@thewrittenword.com)