Finally diagnosed this one. I kept pulling the rotor and checking the inner bearing operation, which seemed fine. Turned out that the inner landing was moving against the bearing surfaces nicely, but the outer landing (where it contacts the race) had jammed and was melting a little every time I drove the car. I pulled the seal and the bearing came out ... in pieces. Don't know if it was a bad bearing, a bad race, or if I installed something incorrectly (although th eleft side is fine). Anyway, problem solved.
