Outer brake pad non-continuous rubbing

So, I have about 146,000 miles on this car. Few weeks back noticed a faint non-continuous rubbing sound due to outer pad (rear passenger side) rubbing on the rotor...as if though the rotor was warped. Took the brake apart and cleaned it. That didn't help. Had the rotor resurfaced. Resurfaced rotor had the same problem. Replaced the guide pins as well, but no fix.
I've searched the forums but haven't seen anything like this problem. And By the way, over the past few weeks that I've been driving with resurfaced rotor and new guide pins, the rubbing seems to be getting worst.
Any ideas of what this might be?
Thanks.

The shield behind the rotor's known to cause that. It could also be uneven brake pads from the previously warped rotor "before resurfacing". The other could just be a really bad rotor that won't get fixed even with the resurfacing. I had to replace a rotor that began to rub again 1 week later after resurfacing. It fixed the problem.

It's not the shield.
Even after resurfacing, when I placed the caliper on the trued-up rotor...the rubbing was still there and visible to the eye. At certain point on the rotor, the pad catches and then let's go.