Autorudder only works when flying, Sean. On the ground you should still be able to use your rudder for taxiing.
Xman123, I suppose your joystick has a twistgrip (you can turn the joystick to the left and to right?) Did you try calibrating that movement and is it still recognised by Windows?
Depends on the joystick. If it has no separate rudder control you need to activate Auto-rudder from the FS9 Aircraft Realism settings. Steer on the ground with the ailerons.