Andy, you have described a perfect installation. Since it is happening with two different servos, the common element is still in the plane. Could it be good old fashion vibration getting to that one servo mount? How about some images from several angles. Is your receiver mounted on foam? I know that Futaba discouraged a complete foam wrap at one time but on one side it will be OK. By the way, I have my Futaba receivers smothered in foam and flying well in 95 degree temps often. Dan.