Hi, I've recently put together a quad with DJI FlameWheel 440 frame, ESCs and motors and APM 2.0 I have few problems: 1. in Stabilize mode it's extremely difficult to hold altitude: when I slightly increase the throttle to avoid crashing the copter continues to ascend and even small change causes it to descend and it bounces up and down. I tried changing the controls but they seem to have no effe…