The ailerons, rudder, elevator twitch or flutter rapidly when I try to control them.   This makes the AC uncontrollable in flight.   This is a new problem that has gotten progressively worse.

Sitting on the runway with the engines at idle and the parking brake on.  When I use my CH pedals to move the rudder it deflects the correct direction and then flutters make and forth from that position to centered and back - many times a second.

The ailerons move the proper direction on the proper wing but then start fluttering and slowly return to neutral - even if the CH Yoke is still turned.   There is no way to maintain a constant aileron setting.  

The elevator never does move to the proper deflection - when I move the yoke the elevator just starts twitching and continues to twitch for many seconds after I release the yoke.  

NO OTHER AC has this problem.

While this is happening to ANY CS 727-100 or 200 I can switch to the CS 757 or CS C-130 and have no problem with control surfaces.  Likewise I can easily and properly control th MS 737 or 747, the Vistaliner 727 or any of the hundred other AC I have purchased or downloaded.

I flew the 727 for a week with no problem, then the problem would occur intermittently and now the AC is uncontrollable all the time.

The same problem occurs with a Saitek ST290 Pro joystick.  

The same problem occurs when I use the NumPad to move the flight surfaces.  The problem even occurs when I start FSX with no Yoke or pedals and use only the NumPad.

This problem occurs when other addons are running or when they are not running.

What do I do?

I have searched this forum for flutter, twitch, "control surfaces", elevator, rudder and find no mention of the problem.

Am I the only one to have this problem?

FSX/Acceleration  VISTA32/SP2 Home Premium
Long time FSX user