Hi Johann,
Would it be an idea to enter a slightly longer distance for the arc in the routing db?
I tried that, it didn't help.
I really dont like such things, as they are only are just workarounds, but it seems the easiest solution until the correct encoding is known.
I don't think the issue is the correctness of the encoding, it's more to do with the fact that the OSM map can contain nodes that are closer together than the Garmin can accept. The thorny issue is how to munge the data so that the GPS (or mapsource) doesn't barf but the map is still usable (connections not broken, etc.) One trivial fix is to delete any way that would otherwise cause a problem. That should stop the garminware from barfing but would not be ideal from the user's point of view because it would break the routing. Cheers, Mark