As mentioned, I believe it's the sound affecting the flying.
I noticed it with my first couple of flights, then I adjusted the levels of several of the sound files and I was flying fine. I had to adjust the airraid, explosions, ship guns, and a couple of other sounds because they were way too loud.
For my system, I also had to select discreet 8.1 in order to get rid of a slight lag between any stick or throttle button and the associated sound, as that really was throwing me off.
mir