We are currently using CM 22.214.171.12400-2 (will be upgrading to CM 7.1(3) in a couple weeks), Presence Presence 7.0(2), and Exchange 2003 R2. We recently set up the Outlook Calendar integration with Presence and users are not able to change their status in Presence, when a meeting has ended early, without either deleting the calendar entry or changing the time for the meeting.
Because CUPS is pulling this information from Exchange. If the meeting is schedule in the CAL from 11:00-12:00. And the meeting ended at 11:45, there is no way for CUPS to know this.. or Exchange for that matter. If the meeting was changed in Exchange to 11:45, then it would update CUPS. But there is no overide, since this pulled from the free/busy information of Exchange.