[This problem just appeared in 5480].

If you look at the schedule in multi-schedule view, all works.  If you switch to single-schedule view, all the appointments disappear.  However, if you try to make an appointment on the single schedule view where you know there is already one, then the Appointment window bitches that there is an existing appointment.

Conclusion: this is simply a display logic problem in single schedule view.

Regards, Tim G