Bump ... I had to move my PC recently and I plugged the joystuck into a different USB port. Of course, AH didn't recognise it as the same stick, so I had to remap everything again.
afterwards, I noticed the same problem, the stick was very sensitive and twitchy, until finally I checked the stick scale, and sure enough, it had reset itself to 100% for this "new" stick. After setting up the stick scale again all is back to normal.