I have SATISFIED pads on my teg with powerslot rotors and when the car is cold the brakes grind like no other, sounds like metal-on-metal but goes away after first couple stops. WTF is goin on, the pads are new and wearing evenly. Is this just because they are metalic pads, should I just get new pads that arent semi-metalic? I've put over 500 miles on them and theres no difference, actually got worse since they were brand new.