I purchased a 2004 Corsa last year and all was well up until the last few months when I noticed this horrendous judder when pulling off. It only occurs just as the biting point is being reached. Once the clutch is more or less up everything is fine. I've also noticed that the car can be hesitant to actually move when pulling off, even when revving fairly hard. My immediate thought is that something has contaminated the clutch plates. Can this juddering also be a sign of a worn out clutch though?