Hi Johan, And yes... I'm fearing the firmware as the culprit too, however, Garmin's maps and other third party maps complied with others compilers work perfectly.... okay, I did not get that before. There is a function in mkgmap that manipulates the values of angles to assure that Garmin gives correct advices at e.g. roundabouts: --adjust-turn-headings I think this might be the reason for the problem. I've compiled two gmapsupp files for the roundabout from your 2nd example, once with (v1), once without this option (v2) Please check if you see a difference. The attached file contains the input file and the different gmapsupp files produced with mkgmap r3336: v1: java -jar mkgmap.jar --route --index --gmapsupp wrong-exit.osm v2: java -jar mkgmap.jar --route --index --gmapsupp --adjust-turn-headings wrong-exit.osm Gerd