If you have the correct pivot arm and the throw out bearing is mounted correctly, then you will most likely have to pull everything out to really see just what is going on. I don't care much for the idea of shims. The throw out bearing should have the clutch disengaged before the pivot arm can get to the pressure plate. Sorry, but it just sounds to me as if you have something in there that is not set up correctly or an incorrect part. Regardless, now is the time to find out before you ruin something.
Ron
