Well it seems now that its the dark he doesn't like - even if I put the floodlights on he's still scared to go out. If I have the lights already on then he can be persuaded out. Most annoying now is that he runs in from the garden to do a poo - or waits until I open the door after being in the freezing cold for 15 mins.
I guess I have to get my timings better so he can't wait to go - we've had a couple of accidents where I missed him squatting. Oh well - he'll get it - I hope