I just bought my Phantom and went out for my first test flight a couple of hours ago. Tried some basic maneuvers, played with GTH feature by turning off the transmitter while it was hovering a few hundred feet away, etc. Everything was great. Then while it was hovering about 20 ft off the ground (in GPS mode), the unit suddenly inverted and accelerated and smashed into the ground. I'm pretty sure I wasn't touching anything on the controller at the time. In any case, I don't think it's even possible to invert the unit like that using the controller (?) Luckily the enclosure itself seems to be fine, but I haven't tried flying it again. I had mounted prop guards, and two of them snapped.. which kind of sucks, but it's better than damage to the main housing. There was plenty of juice (I had just put in a new battery) and the green light was flashing the entire time.. so it didn't suddenly run out of power. Since it inverted, rather than falling somewhat gently towards the ground, it actually accelerated and smashed the ground pretty hard. Luckily it was a grassy field and it wasn't too high up at the time. Has anyone else experienced anything like this? Some other key info: 1) Prior to my first flight I upgraded the unit to the latest firmware (3.14 if I recall correctly) 2) There were large power line transmission towers about 1000+ feet away. Could it have been some kind of RF interference from there?