ah haha, weird. my electics are a bit crummy, when i put my rear demist on, sometimes the rear foglight and left indicator lights come on on the dash, also the rear wiper starts moving really slowly. so i have to turn the demist off. Also all the time when i stick it in reverse the rear wiper goes really slowly too. so i have to flip it on and off again so it resets.
Merry Christmas Piers, sent you a present in the post,