Yet another Sat nav related question. However, I am hoping that this is a little simpler. Press Nav, then 'agree'; sometimes I get a lovely map, but sometimes i get a message "the disc installed is not a map dvd". Eventually, after anything from 1 - 10 reloads of the disc in the boot (trunk) it will work. Does anyone have any clues as to what this tempremental issue could be? Sticky laser? Duff disc? Its a shame because apart from that, at 102,000 miles old, my 55 plate x-type 2.2d se is fantastic!