Update to 1.8.9 just applied from 1.8.8 and breaks site

Hi

Just updated Custom Field Suite to 1.8.9 and now this:

Warning: session_start() [function.session-start]: open(/var/chroot/home/content/67/5743267/tmp/sess_furg5fqh0g51ahq51cm5b428k4, O_RDWR) failed: No such file or directory (2) in /home/content/67/5743267/html/wp/wp-content/plugins/custom-field-suite/includes/classes/form.php on line 42

Warning: session_start() [function.session-start]: Cannot send session cookie – headers already sent by (output started at /home/content/67/5743267/html/wp/wp-content/plugins/custom-field-suite/includes/classes/form.php:42) in /home/content/67/5743267/html/wp/wp-content/plugins/custom-field-suite/includes/classes/form.php on line 42

Warning: session_start() [function.session-start]: Cannot send session cache limiter – headers already sent (output started at /home/content/67/5743267/html/wp/wp-content/plugins/custom-field-suite/includes/classes/form.php:42) in /home/content/67/5743267/html/wp/wp-content/plugins/custom-field-suite/includes/classes/form.php on line 42

Have disabled plugin but do require it.

Thanks
Mike

http://wordpress.org/extend/plugins/custom-field-suite/