Thanks EnglishAl and Pronto.
I remember Human Factors telling me that a pilot will always revert to his original training. I did a flight in the PA28 about 3 weeks ago and it was like going home - so familiar (only forgot one thing - Carb Heat during downwind checks). After a couple of flights in the PA28, I will then be dangerous in the TB20.
It must always be a challenge for those that try to stay current on multiple types. You can always recognise the rental car by the way the driver indicates using the windscreen wipers. Just rather larger consequences in a plane.
CAVOK