i just wanted to say a big thank you to the forum, im a newbie and had just purchased an x5 which i upgraded the navi unit from mk 3 to mk4 and had been having loads of issues, apparently the previous owner had hacked the navboot file and once you put a dvd in it kept resetting, solved the issue today by downgrading to v 29 and upgrading again to v31 and voila working fine....however i lost the bmw roundel tho!! but no fear.....you guys are really the best!!!