I had this problem when I was first attempting to adjust mine as well. It seemed like I had to back the pads off quite a bit more than Avid's instructions claimed.
First, after you adjust the pads out, give the brake lever a couple of good squeezes to set the pads in place. I found that while the pads would sometimes rub right after an adjustment, actuating the brakes a few times would alleviate some of the rotor rub.
Second, and I'm not sure why it worked out this way, but I had an issue with a bad vibration using the BB7's on a cyclocross frame with a carbon fork. I resolved the vibration by increasing the torque on the rotor bolts. I also readjusted my caliper at the same time and found that with the higher torque, I only had to back off the outside pad by the recommended 3 clicks to get clearance whereas before it was more like 6 clicks. Now, obviously this could have had something to do with my previous set up not being perfect too but it sure seemed like a strange coincidence.
BTW, if you search for my thread about the rotor torque and vibration issue, you'll find that Avid stands by their recommendation etched into the rotor (6.2 N*m) even though the manual says 9-10 N*m. They claim the manual torque is a misprint but I had the vibration using 6.2 and didn't after upping it to 9.5. YMMV.