Throttle problems

I have been flying tubeliners for years and upgraded to a Windows 7 64-bit OS a while back. After about a year of successful flying my throttle response became inaccurate at any speed. It will overspeed whether on auto-throttle or manual and even lose speed up until the point of stalling on other occasions. It does not matter the aircraft I use. This happens more frequently at speeds over 200 knots.

 

I have used both the boxed and the Steam version with the same results. I can't understand why this happened all at once. I have tried reinstalling both versions with the same results as well. I have also reinstalled FSUIPC. Any suggestions would be appreciated.

Are you using a joystick/throttle combination? If so, has it been calibrated recently?

I use Extreme 3D Pro joystick and Logitec throttle quadrant. All have been calibrated multiple times. I have had the same issues with or without either of the add-ons.. I have two different pc's one running win 7 32-bit and one running win 7 64-bit. Only have issues with the 64-Bit machine. I have two throttle quads and a Scitech yoke and rudder pedals on the 32-bit machine with no problem Also running Crgsim avionics. Have a home cockpit on the 32-Bit and built a 64-Bit pc for more memory and an SSD drive

Having the same problem with keyboard. I'm a complete noob using X-plane 9. Just now using it again after 3 year hiatus. F2 starts throttle up which continues until full throttle, F1 starts reduce throttle until all the way, uhhh, un-throttled(?). I can find no combination of tapping, holding, or other buttons that will stop the continuous change in throttle. It seems to also be a very rare problem.