Sunnyjohn if you are following a thread you will regularly be using 'last page' or 'go to last post'. If you are then told that you are on the second to last page, the natural reaction is to look at the last one, but that just returns you to the first post on the one you are already on.
Thanks SSK and uffington. I just assumed it was a vagary of Pprune but it doesn't seem to worry me. Should I be worried about that?