I have jrdrones ArduCopter Quad with ArduMega1280, 20A ESC, 880kv motors, sonar. Using the 2.1.0 Alpha software. I have just got it flying for the last month or so, and have flown it a few times with increasing success, total time about 30 minutes. A few days ago, was flying in STABALIZE mode and was able to move around pretty good for 5 minutes or so. I then switched to ALTITUDE_HOLD, and it…