Thanks again for all your responses ! (and if anyone needs tips on skiing - PM me !)
Any advice on how to make the weather good when I'm going skiing would be gratefully received!
As for the landings, don't take any notice of the chap who advised you to change your instructor. Pay attention to his advice about keeping your aiming point in a fixed position on the windscreen, and try to note the point on the windscreen where it is fixed. It's not easy to start with, but it'll come.
If you choose the right aiming point, fix it where it should be on your windscreen and set the power and flaps - you will find that you consistently fly approaches at just the right speed, with just the right rate of descent, and consistently touch down just where you want without really having to try.
It'll stand you in good stead for landing on shorter runways, and very good stead if you ever decide to mix your hobies by flying a ski-equipped aeroplane.