Appointments and send on behalf

Here's the situation, I have user 1 (the boss) and user 2 (bosses assistant)
Outlook 2003 with current updates.
User 2 is set up with access to user 1's calendar, and is set up to be able
to send on behalf of user 1. When user 2 creates an appointment (from her
PC) in user 1's calendar, it does so "on behalf" of user 1 which causes user
1 not to be able to accept, deny, or change the appointment. Is there a way
to change it so the appointment in user 1's calendar is created by user 2?
Exchange Server 2003 if it matters.
TIA