With (set pop-up-frames 't), org-read-date behaves badly, creating calendar in the bottom. (setq calendar-setup 'calendar-only) would fix this, but org-read-date overrides it. A new frame for the calendar. But the frame is split, with the calendar at the bottom, and some random buffer at the top.
Is there any reason that org-read-date is overriding calendar-setup, or could this be made customizable? Tom