DB_DataObject_FormBuilder and crossLinkExtraFields

Hi, I'm using DB_DO_FB for a conference management system which includes four tables: conference_session conference_time_slots conference_venues conference_session_time_slot The final table, conference_session_time_slot, connects a session with a time slot and a venue, and I have my conference_session DO set up with: public $fb_crossLinks = array(

            'table' => 'conference_session_time_slot',
            'fromField' => 'session_id',
            'toField' => 'time_slot'));

and in my conference_session_time_slot I have: public $fb_crossLinkExtraFields = array('location'); That generates a form with checkboxes for each time slot, and a select list of venues for each time slot. When I add a session to a new time slot everything works fine, with an entry being created for the appropriate time slot and location, but when I try to alter a location for an already selected time slot the update isn't completed and DB_DO_FB attempts to insert a new value in the database for just the location. eg. DataObjects_Conference_session_time_slot: QUERY: INSERT INTO conference_session_time_slot (location ) VALUES ( 6 ) where 6 is the value of the location I want to change to, but I expect something like: UPDATE conference_session_time_slot SET location = 6 WHERE id = X Looking through the code I can't see where DB_DO_FB actually works out which updates it's supposed to make for extra fields, so I'm not sure where to go next. Anyone got any ideas? thanks. James. -- James Stewart http://jystewart.net/process/