I don't think we have the same problem as I reduced the travel in my TX down to 100 from 125 and it's within the allowable range now. I recalibrated in control panel, then in the sim and all is well in pixel-land again.

My guess is that your problem is computer related. Maybe try a joystick and see if it drifts out of calibration also which would eliminate your TX. Also maybe delete the driver and reinstall it. That's all I can think of but I'm no expert.