diff --git a/SoObjects/Appointments/SOGoAppointmentObject.m b/SoObjects/Appointments/SOGoAppointmentObject.m
index 6ae3868694..93cb3fd40b 100644
--- a/SoObjects/Appointments/SOGoAppointmentObject.m
+++ b/SoObjects/Appointments/SOGoAppointmentObject.m
@@ -963,13 +963,15 @@ - (NSException *) _handleUpdatedEvent: (iCalEvent *) newEvent
   NSArray *addedAttendees, *deletedAttendees, *updatedAttendees;
   iCalEventChanges *changes;
   NSException *ex;
+  WORequest *rq;
 
   addedAttendees = nil;
   deletedAttendees = nil;
   updatedAttendees = nil;
+  rq = [context request];
 
   changes = [newEvent getChangesRelativeToEvent: oldEvent];
-  if ([changes sequenceShouldBeIncreased])
+  if ([changes sequenceShouldBeIncreased] || [rq isICal4] || [rq isICal])
     {
       // Set new attendees status to "needs action" and recompute changes when
       // the list of attendees has changed. The list might have changed since
diff --git a/SoObjects/Appointments/iCalEventChanges+SOGo.m b/SoObjects/Appointments/iCalEventChanges+SOGo.m
index f07c42a1eb..51e3ec628b 100644
--- a/SoObjects/Appointments/iCalEventChanges+SOGo.m
+++ b/SoObjects/Appointments/iCalEventChanges+SOGo.m
@@ -30,7 +30,7 @@ - (BOOL) sequenceShouldBeIncreased
   static NSString *properties[] = {@"organizer", @"startDate", @"endDate",
                                    @"due", @"duration", @"summary",
                                    @"rdate", @"rrule", @"exdate", @"exrule",
-                                   @"status", @"location", @"rid", @"timeStampAsDate",
+                                   @"status", @"location", @"rid",
                                    nil};
   NSString **currentProperty;
   BOOL updateRequired;