I recently bought a phantom 2 v2.0 and took it on its maiden flight yesterday. I calibrated the compass and made sure firmware was up to date. I flew it for awhile then landed it and took it off again. I then flew it until the battery was at 1 green led and tried to land it. The props were about to shut off when it launched up out of control into a tree. The prop and prop guard broke. But I flew it again and it's fine. I was flying in gps mode. What caused the flyaway and what do I do if it does this again? Would switching into Atti or Manuel mode prevent or stop a flyaway?