(last year's statement) In line with the Oyster PAYG off-peak fares,
there will be a change to the times when South West Trains' Super Off
Peak `turn up and go' ticket is valid for journeys from London.

http://www.southwesttrains.co.uk/any...k-advance.aspx
click on -Off-Peak and Super Off-Peak fares-
[...]
From Monday 4 January 2010, the return portion of a {Super Off-Peak}
Day Return or Day Travelcard will change. You cannot use it to leave
London Waterloo, Vauxhall, Queenstown Road or Clapham Junction to
stations outside London Zones 1-6 between 16:00 and 19:00, Monday to
Friday. A map of this area is available here. If you wish to make your
return journey during this time, you should buy an Off Peak Day Return
or Off Peak Day Travelcard
==

So no need for an Anytime Day return

Is this different to the rule as used in North London ?

Seems easy to get round in most cases by taking the first train to
Richmond, Wimbledon or Surbiton and then the train you want.

My previous scheme of buying a day return to Surbiton plus a London
zones 1-6 ODTC also.
The new possibility is a day return plus PAYG Oyster touching in & out
at a Surbiton validator (£3.20+£4.90 so capped at £7.50 - £5.00 with
Railcard)

--
Mike D