Phantom 2 (latest version) with H3-3D gimbal and GoPro Hero 3+ Black. All the latest firmware. On most of my flights the gimbal rolls hard over and then returns to level. It does this very cleably and quite often. It however usually does settle down and stop; usually about 10 minutes into the flight. It can be seen in this short video (http://youtu.be/5BKbTd0Il_4) taken a few seconds after takeoff. The aircraft is initialised on a flat platform and not touched until ready to go (camera started prior to booting the Phantom). It has never been crashed or abused (yet). It has managed the occasional flight without a problem. Any thoughts? Returning stuff at this time of year a nightmare so I want to exhaust all avenues first. This seems different to other problems I have read about.