I'd say that the pads are too thick. I used to have the same problem everytime I replaced the pads on a highly modified Audi 100 Turbo I used to have. Simply get a large sheet of very abrasive sanding paper, put the paper on a flat surface and rub the first couple of thou off the face of the pads until the discs turn freely.
Front pads used to last a maximum of 7000 miles on that car, discs needed reskimming every 15,000 and replacing every 30,000. 0 to 60 in just under 7 seconds but it couldnt go round corners so it was belt along the straight, brake like mad before the corner, then haul the barge around it and floor the throttle again......having done 169,000 miles in it I must have enjoyed the ride......
Cheers,
Tony
