In my organization we use public folder calendars to schedule and plan meetings and activities for our various conference rooms. I have one user in our HR department who is unable to view one particular calendar, everyone else can view this public calendar just fine. It's not a problem with permissions, she is the designated owner of the folder, but the folder does not even appear in the list of folders for her.
It is not a problem with her outlook profile. We have deleted and recreated her profile on multiple workstations (we do not use roaming profiles).
We run Exchange 2003 with Outlook 2003 clients. She was able to view the folder just fine up until a couple of weeks ago. She is not aware of any change on her end that could have made a difference and we made no changes to the folder or her active directory profile. Our active directory runs in 2003 Native mode and we currently only have one exchange server.