Cheers guys, I'll double check your suggestions and report back. Now that you mention it, I don't think I've had the problem when I'm planning a route (I just tend to put the maps on when I'm driving around cos it looks cool!). I just thought I'd been lucky it hadn't occurred when I was planning a route.

It is a factory fit nav (and it's an E46 - am I still allowed on the forum? )

Thanks again.

Simon.