In version X, the controls are updated 100 times per second (same as the physics update).
In previous versions, they were updated at the frame rate.
So now, using smoothing, for all frame rates less than 100, your in-game steering wheel catches up more quckly with your controller.
I think the solution is simply to allow more steer smoothing. I've just raised the maximum to 0.95, so you can try that in this evening's version X3.
Also note that with a gamepad or joystick, you should set "Wheel turn" to 90 degrees and use maximum Wheel turn compensation.