Doug, perfect, at least now I know that there's nothing I can do about it. I spent ages trying to turn off this "new feature".
It would make more sense to be able to disable this though, if we wanted, and keep it the way we were used to. Invariably I look back at a photo, two or three back, and then go shoot, look back at the monitor, only to not see the new image come up. This is a pain if I'm up a ladder, and I have to tell someone to go click on the last image.
Anyway, thanks Doug for clearing up where the issue lies.