Hi Franco, there are 2 weird things in your maps. First is a subfile SRT, which doesn't belong to any tile or index. It is present in both files, bad and good img. It is probably ignored by GPS. Maybe mkgmap writes SRT even if MDR is not present? Second distinction is that bad img is missing MPS subfile, which is kind of directory with names of combined img. This could be the reason for different name in GPS, but I think the map should still work correctly. Again, maybe there is some kind of limit of tiles, that mkgmap remembers, when creating MPS subfile? So IMHO the problem is with combining your map into single gmapsupp.img. You could install map for BaseCamp and then use MapInstall for creating combined map. -- Best regards, Andrzej