Ahhh.... now I see. I don't think anything is wrong. If you move your stick around you may see this "jumping". As you chang direction you should notice your pilot's "head" bobs in reaction to the change in G forces. In addition, when firing guns the recoil of the weapons will shake the plane around too.
As a general rule, you should never be shooting zoomed unless at very long ranges IMO. When you zoom, you loose your perspective I find, and it becomes much more difficult to score hits. I recommend you use the zoom mode to see more distant targets to guage their flight path and attitude, but when firing always do so from your normal forward view. Give it a try, and you should still see your screen "shaking", but you won't notice it as much if you are not zoomed way in.
