Routes recalculating

Hi,

I prepared my routes for a trip on my laptop. My Zumo and laptop have the same map installed, so when I transfer
the routes from my laptop to my Zumo the routes are identical.

However I want to take another netbook along on my trip. So I installed the exact same map on the netbook, exported the routes from my
laptop and imported the routes on the netbook.

Also there the routes stay exactly the same.

Now when I try to copy the routes from the netbook to my Zumo I get a message saying:
Your route(s) may not recalculate to match the map on your device because the map is still loading.
Do You want to continue?

After pressing yes, the routes are downloaded to the Zumo, but when viewing the result there the routes are worthless.
Only straight lines apear between the waypoints.

I tried removing the map again from the Zumo (from the memory card), and reinstalled the map from the netbook, but the
result is the same.

Any help would be appriciated.....