hmm it seems you are leaning a little too far forward and you should put a little more weight on your heels instead of your toes. Of course I have only read books and never done showjumping myself. I read about it quite alot though because I love it. Keep up the great work though. Your doing pretty good.
I agree, you should put more weight in your heels, it also looks as if your legs are sliding back a bit, although it's hard to tell by the angle of the pic. Keep your legs in the same position as though you were riding three point.