polikarpov i16, I have to disagree with you. My airplane is in no way stalling when it snaps. Even when pulling up from a high speed dive, the plane snaps to the right, indicating that slow speed stall is not the issue as you suggest.
Maybe its not a true snap- maybe its a roll to the right. Either way, the plane is in no way approaching a stall speed. I think what is happening, is that the right elevator is moving slightly differently than the left elevator. I am also sure that torque has something to do with it as well.