Luckily there was a nice easy fix:
- Quit Outlook
- Click Start->Run
- Type “outlook /cleanreminders” without the quotes and hit OK.
- Outlook will then launch after cleaning any corrupt appointments.
- Quit Outlook again.
- Click Start->Run
- Type “outlook /cleanfreebusy” without the quotes and hit OK.
- Outlook will then launch after cleaning any corrupt free/busy slots.
- That’s it.
4 of my employees had this problem with Outlook 2000 and Outlook 2003. The above fix worked first time for all of them.