We're using the latest on D7 to have a nice RSVP form for an event. We made a custom status 'Not Attending' and of course have 'Registered' as the other status. The form has 4 contacts on it, cloned, all with the same stuff. No prices, just name/email/phone for 4 contacts with the RSVP field (civicrm_1_participant_1_participant_status_id)
When they first submit the form their choice is saved, works great.
But, when they return to the form, and submit again with a change in RSVP, the update is not reflected on their civicrm participant record.
Is this by design, or an error I have made? I assumed it would be cool to let people change their mind!