Ok, I have to admit....I'm baffled.

My donor was a 2002 so I am using the rear 2002 hubs and spindle assembly. I ordered the 2006 rear 2 piston calipers which nave not arrived yet. I removed all the parking brake stuff. Now when I mount the 2006 rotor and tighten it down with the lug nuts (even before mounting the rear wheel) the rotor locks the hub right up. Unless I space it out with washers, it will not rotate? I measured the backspacing on the 2006 rotor and it matches that of the oem 2002 rotor. When I put the oem 2002 rotor on it also locks up? What am I missing? Is there something within the guts of the parking brake that backs the rotor off? I can't figure out why it is locking up? Any suggestions?