This drives me crazy. At the very least the function shouldn't be called 'Duplicate Page', because it does nothing of the sort. Maybe duplicating the settings onto a new page is helpful to some, but I'm just today having to recreate a substantial amount of information on a page because I can't copy it over. I think it might be possible to duplicate the entire campaign, and then transmogriff over the page from the other campaign, although I haven't tried it yet... But I'm going to now.