Could be a speed sensor going off, possibly something with the differential too. When I had my 2004 Impala, sometimes the traction off (whether I toggled it or not) and ABS light would come on and stay on. Only way to clear it was to restart the car. Took it to the dealer I worked at, and they found the left rear speed sensor was going bad. Spent about $80 and replaced the wheel hub on it, and that fixed the issue. Those cars had the sensors built into the hub themselves.
In my Mustang, sometimes when I was accelerating and hitting a bump (happened all the time on an exit ramp on the way home), the car/tire track icon would flash, and the motor would cut the acceleration. Possibly some kind of anti-wheel spin/anti-hop function, though I would drive with the advancetrac all the way off. After the car straightened out, or if I let off the gas a bit, it would resume normal driving.
On the Mustang's the speed sensors are separate from the wheel hub, but the wheel hub can still pose an issue with the ABS system. In the picture below, the teeth on the hub is what the sensor reads (pretty much a binary wave to the computer):
Sometimes if those rings have debris in the crevasses, it can throw the sensor off. I'm not sure how the rear reads for the ABS, but I'm guessing there are ABS rings on the axle (never looked at it closely).
Probably take it to a dealer to see if they can pull any codes/readings from their machine that yours isn't seeing.
