The send updates only to added or deleted attendees issue is constant. There could be a patch but here are three suggested workarounds.

1 - Go offline first. The update will go into the Outbox. Delete the update from the Outbox. You then ask the people you deleted to remove the meeting from their calendars. http://www.slipstick.com/outlook/cal...-send-updates/

2 - You can try unticking in the Scheduling Assistant rather than deleting names.

3 - One I no longer have to use, so I may not remember the steps correctly. Save without sending. Try to close then send the update.