I get a squealing sound from mine ever since about 100 miles! Pulled the caliper and hit everything with some brakekleen squeal goes away...until the next ride! I'd pull the caliper and see if you got a small pebble lodged in there!
Check the pads and for rocks to be sure, but the 700 (and to a lesser degree, the 500) have always been notorious for this. It's a consequence of sending braking force through the diff.
I have it too, cleaned the calipers and added anti squeak to the pads and it helped a little bit... I bet the chatter is mainly from the lash in the ring and pinion possibly. (like DG Rider mentioned).