Hi Marko,
The Nüvi user replied today that the map that I generated with r1392 (MAX_ARC_LENGTH=35000) on November 16 works for him. He did not state the date of the map, so he could also be referring to r1366 patched with MAX_ARC_LENGTH=39062, from Nov 11.
Well, I chose 35000 because 39062 is too much of a magic number! However, it would be good to find what the real problem is here. As I reported before, I have a useful patch that removes nodes that aren't really needed but I can't use the patch because although the maps are fine for mapsource and the etrex, the nuvi barfs on them! It's bizarre. I wonder if there is some stupid bug in the nuvi that we're hitting. I have tried lots of different things (changing sizes of data tables, etc.) but nothing seems related. Grrr. Cheers, Mark