I've already noticed that my GPS light won't come on at times last week, so I re-seat the daughter board and solder up the power pins. Today, my heli did some sudden 90 degree yaw turns. I later looked at the tlog, and there were no mx,my,mz data. I then looked at the live tuning data and confirmed that some of the 12 pins connections to my daughter board was loose.
I removed the daughter board from the APM2 and bend the data pins a little and put it back in. Let's see if it hold.