steve, this chattering also happens at the flying field when doing the normal range check, when the tx antenna is down i get about 10 foot away and they start chatting but the range is good and all controls work fine. there are no problems flying the model but i really dont feel safe with this problem as anything could happen sometime, if these ds-821 servos would shut up i would feel relaxed. the way these start chatting seems like a range problem but as mentioned i have good range.