I replied in the other thread.
When I lowered mine, it also upset the xenon headlights. They were pointing straight into the ground and only lit around 20ft infront of the car. The first time the car was at the dealer, they said the lights were fine but it was up again a couple of weeks ago and they reset them. They are fine now.
I think this was something to do with the self-levelling sensor on the front arm of the car being upset when the springs were fitted, possibly the same has happened with your traction control?