thats interesting what you say about the switch replacement, as on Euro Right hand drive models, i.e here in the UK. To switch the parking lights on, the switch has to be moved one or two clicks anti (counter?) clockwise. Turning clockwise turns the side lights and headlights on respectivly. One click out and the front fogs are on, 2 clicks out and the rear fogs are on..with the orange light in the actualy switch illuminated as well.
Maybe the change of the switch has caused the problem, as the fogs are automatically cancelled when the lights are switched off.