I've got a somewhat critical situation going on. I'll lay out the details as best I can:
Brad and Brett share a secretary, Devvi. Their calendars are shared with her. Sometimes their appointments need to be rescheduled. Devvi goes into their calendars and moves the appointments to the new time. What seems to happen though is that some of the appointments disappear. They aren't on Brad or Brett's Blackberries. They're not on their Outlook calendar. They're not on their Zimbra webmail calendar. They just seem to go away.