Has anyone had this happen to them? At home connected via USB the APM 2.5+ and the Ublox LEA GPS get a fix almost instantaneously in my back yard pointing in the correct direction. When I'm out in the field, the and I power up via Lipo battery, the GPS takes longer to get a lock and the direction of the plane is reversed 180 degrees - as I view it in APM via 3D radio connection (and yes the APM is pointing in the correct direction toward the front of the airframe). In the field the GPS is sitting right next to my receiver and the 3D radio. Is it possible that the other electronic devices are interfering with the GPS?
That error in direction means I can't fly in any other mode than manual. Any help would be greatly appreciated. Thanks.