We use outlook 2003 on exhange 2003.
One of our users, (user 1), calendar entry times are 1 hour early. For example, if I setup a meeting from 9:00 am to 10:00am and invite 5 attendees then it will appear correctly for all except user 1 which will appear as 8:00 to 9:00am.
The same happens if user1 creates the entry and invites attendees. For example, user 1 invites 5 attendees to a meeting at 9:00am to 10:00am. All attendees recieve a time of 10:00am to 11:00 am.
Basically user 1 is 1 hour ahead of everyone else in any case.
We all have the same OS and same version of outlook.
All regional settings and timezones are correct on user ones machine.