Brake Wear Light still illuminated

[Frodo]

Just finished doing some brake work, at 80k miles. At all 4 corners, replaced the rotors (Zimmermans) and pads (EBC RedStuff). Also, on the fronts (where pads were less than backing plate thickness) I replaced the sensors (Sebro) since the warning light had started coming on. Didn't bother on the rears---there was LOTS of brake pad left.

Now the warning light is consistently on. I haven't pulled the wheels off yet to take another look, but I'm sure everything was put together correctly. Is there some common problem that I should look for? I can't even reset it with my scanner---not technically a CEL I guess, or a "safety issue" deemed too important to be reset by anyone other than one's dealership (or other shop equipped with the proper PIWIS tester.)

Funny thing is the consistency of the warning light. When I had next to no pad left on both fronts it was on for awhile, then off for awhile, then back on. Now it's ALWAYS ON..go figure.