Were the brake pad wear sensors replaced? Sounds like you've got a bad one somewhere.
There are 2 types of wear sensors, and one has a higher temp. capacity. I didn't know this until I had my 500 out on the track, and after 4-5 laps my pad light came on! At the end of the session I popped a wheel off in the paddock, and found I'd roasted ALL of the pad sensors, such that the wire coating had melted off and the wire within was grounding out to the metallic brake pads.
The pads are the only things that'll illuminate that particular warning light-good luck
