Just got my last replacement mavicair in the mail last night, just got thru testing it at the park, for some reason if drifts backwards without my touching the controls, the sensors are working properly and I did a compass cal twice, change batteries three times, on one of the batt change the drifting was to the right, I’m keeping the prop guards on just in cassette but 5he guards pull too much weight and I’m not too keen flying high in the sky, I’m wondering if this problem is in the remote or is the firmware on each battery different?