At that mileage it would be a warranty thing. Does it sound like it's coming from one particular wheel or all of them? There might be some dirt built up on the flanged side of the pads if they haven't worn past those flanges yet -- try spraying the heck out of each calliper with a pressure washer (rinse water, not soap), let it dry for a little while, then take it for a drive and see. Could also be cracked pads. Are the rotors warped at all (pulsation during braking either felt in the seat or in the pedal)?