Renault clio dynamique,when i slow down some times brakes are fine,but have noticed on a few times that the 'abs' kicks in when it shouldnt,even at normal braking when coming to a stop--say at the traffic lights?

ive got a 02 clio extreme and have this problem, i can start the car and drive it to the end of my road which takes a whole ten seconds, come to a stop at the bottom but with the abs on???? :S havent got a clue what this is, the only thing i think it could be it brake dust or wet and damp disks and pads, maybe? if you find out let me know. cheers