Where we used to see this problem crop up most was when employees accessed their Outlook 2003 calendars at work; and then accessed calendars from home or elsewhere using Outlook 2000. Another way this would happen is when opening Outlook from SSL VPN and not having the ViewMail client loaded on the home PC. One way we circumvented the problem was to have users not leave Outlook 2003 open at same time, meaning close/exit Outlook 2003 before attempting to open with another version of Outlook.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...