Hi Mark, I'm not sure if this is good or bad news, but the Nuvi works!
Just to be sure, I'll check my Nüvi this evening. Please do, it would be useful to know if a real GPS has the same problem (my guess is that it will).
It also works out of the box, routing perfectly, when I route from home to my parents (MapSource didn't do that correctly) and to my wife's family (where MapSource did not route at all). So this seems a MapSource issue with the map, not a generic mapping issue. I could check/doublecheck the MapSource settings (i.e. check if there's any caching, remove and reload the TDB file again etc etc). Will do that, but as my Nuvi works, it's not high on the list. And now for something completely different: I think the mailing list noticed some time ago that bike routing is a wholly different thing on the Garmin, right? I'm still getting weird results when I let the Nuvi route by bicycle - simple routes will have the weirdest deviations, letting you drive 35 kilometers where the regular Garmin map has a 14 kilometer route. Now this regular map has no knowledge of bicycle paths, so sometimes the routing is wrong because of that. Anyway, I'm pretty confident now that the routing by car is pretty much as expected. I will keep using my Garmin for reference testing, however, and tell my experiences here on the mailing list. Back to the original topic: if you want me to do anything on the weird route, please tell me so. Thanks for your great work again! Best regards, Valentijn