Well this is weird, I have two different XP machines with Outlook 2003.
One of them automatically uses Zimbra for everything when I install the plugin - it automatically removes my email & calendars (kind of annoying actually). This machine was installed on a user with admin rights.
The other will allow me to add Zimbra to Outlook for email, but it is not interested in calendar events. This was installed as admin but added to a non-admin user.
Any idea how to find a middle ground here? If I delete people's calendars & such, it will not be good. At the same time, the calendar is the main reason for using Zimbra, so if it doesn't work at all that isn't good either.