I am using the Crius AIO pro board and running mpng's port of APM on it. It has worked flawlessly before but after a major crash and some modifications to the platform regarding changes in props, weight, reflashing, migrating from 3S to 4S battery and so on I don't know if the crash is the problem. Maybe it is just in the settings?
The copter flies super nice in stabilize and ACRO but when I engage Alt-Hold it goes nuts. So far I've only tried it for a couple of seconds before I feel like I have to go back to stabilize. The copter switches throttle at what seems random, falling at points and others climbing.
The baro seems unharmed and I've covered it nicely with foam not letting any light in and still giving it room to breath.
Here are some logs that I don't really understand. Looking at DroidPlanner while flying the altitude seemed to fluctuate a lot and at points reaching below -10 and above 20 when I'm only been hovering above ground. Testing the baro in the apartment and lifting the platform from floor to roof it seems go give nice readings between 0m and 2.2 (as high as I can lift).