I've found another defect in the P2 firmware that causes problems in the H3-3D gimbal. If your gimbal has problems with a drifting horizon, this issue probably effects you. Some important things to note: The Phantom 2 supplies inertial movement data to the H3-3D to help it stay level. The Phantom 2 had a change to fix declination offset in firmware 3.06 and up. The 3.06 firmware adjusts compass data for declination offset and remembers it between flights. The H3-3D will exhibit loss of level horizon when the compass data is poor. Videos of TBE show significant loss of horizon in the H3-3D. The H3-3D works normally if used in the same location. The H3-3D will exhibit horizon drift if you take it between areas of different magnetic declination - e.g. from LA to Chicago to NYC. Conclusion: Compass adjustments stored in memory by the Phantom 2 are causing horizon drift when the Phantom is used in different areas. This has been tested and confirmed on two different Phantom 2 / H3-3D systems. Both exhibit exactly the same behavior. Used in one location, the horizon is consistently level. Once used in an area with a different magnetic declination, the H3-3D will exhibit issues with horizon drift. I will experiment with reseting the FC on the Phantom 2 to see if that removes the memory effect on the gimbal.