Thanks for the replies guys, now works a treat.
I had just upgraded kazaa from 1.7 to 2.0, forgetting that the old one had been stripped of all its attendant rubbish following instructions from here some months back. After reading the thread re : Ad-Aware, I installed it and ran a diagnosis. You can guess the rest, 'bonzibuddy' and his mates were back. After deleting those and a few other interlopers, hey presto, smooth high-speed scrolling.
Cheers everyone.
