Cannot get appointment for Calendar item which has changed from Tentative to Accept (EWS 2007)

Setup a room mailbox to automatically reply to meeting request

Setup a delegate and have it accept tentatively until that delegate responses  

Then book a meeting with that room.

When I query EWS and get the itemEvents for the room I get an event for the appointment which shows the rooms Tentative response

However after a delegate accepts the response I do not get an itemEvent which turns into an appointment indicating the room's status has changed from Tentative to Accept

Code:

I have my pull subscription set up and feed it into my GetEvents wrapper

public Dictionary<PullSubscription, IEnumerable<ItemEvent>> GetEvents(PullSubscription subscription) {
            Dictionary<PullSubscription, IEnumerable<ItemEvent>> mailboxEvents = null;

            GetEventsResults eventsResults = subscription.GetEvents();

            if (eventsResults == null || eventsResults.ItemEvents.Count() == 0) {
                return mailboxEvents;
            }

            mailboxEvents = new Dictionary<PullSubscription, IEnumerable<ItemEvent>>();
            mailboxEvents.Add(subscription, eventsResults.ItemEvents);
            return mailboxEvents;
        }

I then take the list of ItemEvents and turn them into appointments to further process them

            Appointment appointment;
            try {
                appointment= Appointment.Bind(exchangeService, itemEvent.ItemId.ToString());
                ExtendedPropertyDefinition prop = new ExtendedPropertyDefinition(DefaultExtendedPropertySet.Appointment, 0x8238, MapiPropertyType.String);
                PropertySet psPropset = new PropertySet(BasePropertySet.FirstClassProperties) { AppointmentSchema.Subject, AppointmentSchema.Body, prop }; //, AppointmentSchema.ModifiedOccurrences, AppointmentSchema.DeletedOccurrences, AppointmentSchema.Location, AppointmentSchema.Sensitivity
                appointment.Load(psPropset);
            } catch (Exception ex) {

                eventLogger.WriteToEventLog(EventLogEntryType.Warning, 108, "ExchangeDataAccess error GetAppointment(ItemEvent itemEvent): " + ex.Message);
                appointment = null; ;
            }
            return appointment;

*NOTE*

This same call flow works fine for 2013 EWS.  I receive an itemEvent for that room mailbox which translates into an appointment that lets me know the room has now Accepted the request