I have the same problem as you, i have 5 cats, 4 of them dont bother me but one always has to jump up and be annoying. I have tried just being persistant and putting her on the floor each time, but she either doesnt learn or enjoys annoying me lol my mum just told me to spray her with water each time she does it, then she will learn not to jump up, but i havnt got the heart to do it so if you find a useful technique please say