You may have got grease or oil on the friction material on the clutch.
If it shudders a little on take off around the friction point.
Or the teeth on the presure plate are cactus.
Or the thrust bearing is rooted (you will hear noises when the foot is off the clutch and it goes away when you put the clutch in).
In any case its take off the f'n'gear box again for you.
