Was the clutch cable adjusted correct? Do you ride on your clutch pedal when you're not shifting gears? I ask this becasue I have a freind who always rest his foot on the clutch pedal and he has ruined his throw out bearing with every new clutch. I didn't know why they were going bad until I saw the way he drove. Plus make sure you have the correct throwout bearing. If the fingers on the pressure plate are flat then the throw out bearing's contact face should be round and vice versa.