I had the very same problem with the Real Flight 7 controller that was conflicting with FS9. When I started FS9 there was na erratic and autonomous by itself throttle movement so that it was impossible to pilot a plane. I only discovered the solution of the issue after reading your post.I was thinking of a kind of misterious vírus or so. The problem also showed up with CombatSim3. I had the Real Flight controller pluged for a while without problems but a few days ago the issue started in every flight.
Thanks.