Is it just mine.... Every now and then normally in intermittant mode the wipers appear to hit each other briefly at the bottom of the screen just before they start to come up again. Doesn't do it all the time. no set cycle to it either. Weirdly it almost never seems to do it when the wipers are on constant when its raining.. Also there are no marks on the edges of the wipers to suggest they are hitting each other.. Any ideas ???