I have similar problems in Finland maps. Driving from Kokkola to Vaasa 123km. Navit didnt found route first pos blocked. When i was drove about 60km it finally found route. Then Navit says that next turn was after 10km, but i knew i have to drive same road almoast 50km more. At Navit when look at map at the same spot where it claims that i have o make turn it seem that the half of the road was gone, but when looking the same map on the internet where i took the maps the road was okay.

I have tried to take map from Planet extract and Cloudmate and the problems exist on both maps after adding them to Navit, so it seems that the problems is in Navit