If your wheels are held on with bolts like they are on the SLK's, check the ends of the bolts for damage. If the bolts are too long due to a thinner "hat" on the disc, your bolts could be contacting the parking brake parts inside. The bolts are VERY length critical. I would also look at the flathead screw that holds the disc in place before you bolt on the wheel.
If the bolts show any damage, check the parking brake components inside as well.
Of course if you fellows are using studs and lug nuts, forget the above...