When a game device is attached to windows XP and visible under Control panel -> Game controllers, that device takes preference over the SpaceNavigator making the Space Navigator no longer function. As soon as the Game Controller device is removed, and the Game controller area is empty, than when the viewer is started the SpaceNavigator is recognised and works again. As in case of one device active under game controllers, there is no option to select under joystick settings the Space Navigator, only the by Xp recognised device is visible under joystick settings in the viewer. Solution, make a dropdown so that the space Navigator can be selected as an active device when the pc has also a Game Controller device attached and active (OK)