I have read about this here in the forum and I have the same problem.
It was the same with my MK3 navi, as it is with my new MK4 navi.
It seams like the problem are in the software because I can se the roads on the map and my position , but I got no guidance eather with voice or by arrows.
Here is a lot of clever people in this forum who can change logos and ad speed cameras. So please solv this problem because BMW is not listen to us customer