Thanks to NZ445 for explaining the reasoning behind using less flap so clearly (and better than I was about to).
But The Scarlet Pimpernel reminds us that the flaps are there for good reason and that without them airspeed needs to be increased not just at the flare but also at touchdown, otherwise you may get the problem I encountered.
So it's probably a good idea to keep a reasonable amount of flap on.
I was taught to keep 20F on a C152, but had heard suggestions of using none, and this had worked well before when I kept the airspeed up. However, I will be sticking to 20F from now on.
Thanks for your input folks.