5ks, dragging rear brake

["Steinbrueck, GL" <steinbru@VNET.IBM.COM>]

I posted a few days ago:
>The RR brake caliper seems to "drag" occasionally, enough that the pad
>life was reduced considerably on one side.  The piston does not leak,
>and does not seem frozen --it retracts and moves in and out easily.  I
>checked the new pads after a short trip (under 50 mi), and can see that
>the inner has worn unevenly.  It appears that the bottom of the pad
>contacts the rotor, while the top does not.  I re-intalled, and
>presently the brake is not "dragging", but I'm sure something is not
>right.  Any ideas or advice?

Having received no reponses yet, let me add:
The drag is still detectable upon rolling to a stop.  It is intermittant
but frequent.  It seems to relent upon braking in reverse.  The caliper
rails are clean, no wear on the caliper itself is apparent, there is no
warpage.  I had the rotors dressed, they are still well within the
service limit.  The guide pins are clean and the boots are intact.  I do
notice a tiny bit more "play" in the upper compared to the lower, but it
could be my imagination.  The parking brake is free and adjusted
correctly by the book.

I'm getting good at zipping the pads out and retracting the piston.  I'm
NOT getting any better at seeing what the problem might be!  --help!
--Gary ('86's: 5ks&5ktq)