Hi all, I realise it's been some time since this thread started but I've finally worked out what the problem was and thought it might be helpful if anyone has the same problem. After trying everything I could think of around the audio system and through the Nav screen settings, I finally got round to checking the Nav Discs themselves. Two came with the car - a 2004 for mainland Europe (obviously the original but not a lot of use in dear old blighty) and a 2012 disc for the UK, which was in the drive when I bought the car. Both looked very similar until, after some close scrutiny, I realised the 2012 UK disc was not entirely legit. When I loaded the 2004 disc and entered a continental address, hey presto, a calming female voice told me to turn left in 50 metres! Comforting to learn that there's nothing wrong with the car and it's just a dodgy bootleg disc. Now all I've got to do is find a recent Nav disc for the UK that doesn't cost a fortune. Thanks to you guys for your help and making a newbie feel welcome. Cheers!