I have a problem opening a particular user's calendar in Outlook 2007 / Exchange 2003.
I've been granted Publishing Editor rights, which work fine with other users' calendars. But trying to open this one user's calendar gives the following error:

I am wondering what are the probable causes for this error? I suspect a corruption in my OST file that prevents opening this calendar. The reason is that I can remember using this calendar in the past. Other users can also open the calendar.