Having a few teething problems with the navigon. Thenavigon is temperamental in showing car info (e.g. consumption in mpg). If the navigon is already attached on the cradle when I start the car then I get no car info for that journey. However if I start the car, then attach the navigon then it seems to work. On one occasion the navigon was giving false info about open car doors, again I had to detach from the cradle and reset before it worked. Anyone else had this problem or have a fix for it? Perhaps I have got a faulty unit?