Networks

I have two users in my office that are having Calendar Delegation issues in Outlook 2003. One user is the delegate for the other and has full Editor privileges on the shared calendar. She can create appointments and invite people to them and it will reflect in her bosses calendar. However, when she goes to update/change the meeting on her bosses calendar, everyone who was invited will get the update but her bosses calendar will not reflect the changes, nor will it show who has accepted the meeting.
We have over 1,000 employees working off of an Exchange 2003 server, and since she is the only one having an issue I believe it is a problem on one of their machines (but I could be wrong). Our exchange administrators have gone over both their accounts and say everything looks fine. I've never seen this before and have tried everything I could think of to fix this (rebuilt/repaired OST, command line switches /cleanprofile and /cleanreminders, changed from cached mode to non-cached mode, rebuilt profile, reinstalled Outlook; all on both machines). I'm frankly out of ideas.