I have users who are unknowingly scheduling meetings over top of meetings with other users. When they schedule the meeting, it shows that the other user is free but they are actually already scheduled to attend other meetings.
I checked to make sure the users' Free/Busy settings are correct. It is set to publish and update every 15 minutes. Everything looks good. The only way we've figured out how to fix this issue is to remove the cached version of a person's calendar and re-add it.
Any other ideas as to why this may be happening?