I've been flying a P3P for a few months now, and just got a P4 and finding that it's not nearly as stable in flight as the P3 is in the same conditions. For example, normal take-off / hover without touching the sticks results in very noticeable change in height and position; it doesn't hover in place as the P3 does reasonably well. It drifts higher/lower as well as laterally. This is generally true throughout flight. For example, if I lock a course and fly fwd/back the P4 drifts off course ends up in a very different location on return than on the fly out. The P3, although not 100% precise, flies the same locked course out and back gives me a fairly straight line and returns to the same point. This is all while flying the P4 and P3 in the same location at roughly the same time; one, then the other. Any thoughts on troubleshooting / remedying this? All of the firmware updates have been applied, compass calibrated, strong GPS signal (18 satellites). Thanks.