I have no idea what has happened, but the photo gallery was working a week ago. Now I'm getting these errors:
Warning: session_start() [function.session-start]: open(/tmp/sess_6b77c622a702a7fd46fa1a83d0d6ce31, O_RDWR) failed: Permission denied (13) in /home/preacher/public_html/photo-gallery/plog-globals.php on line 18
Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /home/preacher/public_html/photo-gallery/plog-globals.php:18) in /home/preacher/public_html/photo-gallery/plog-globals.php on line 18
Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/preacher/public_html/photo-gallery/plog-globals.php:18) in /home/preacher/public_html/photo-gallery/plog-globals.php on line 18
Is this a file permissions problem? (Host has been tampering with file permissions.)
Have you contacted your webhost about these issues? It sounds like they have gotten something squirreled up with how sessions are handled on your server.
Make sure you give them the error messages you posted above when you contact them.