I don’t know if this has been raised before as I am new to the list, but when I try the latest version of mkgmap (r2328) with the latest version of Mapsource (6.16.3) I am unable to transfer maps to a device from Mapsource. I am using Windows 7 service pack 1, 64 bit. If I overwrite with an older version of mkgmap (r2168) I no longer have the problem. I have tried the older version R2316 and got the same problem. I have been seeing a similar error with mapinstall (on a mac). I have been building maps, installing them (mapmanager?), viewing with basecamp, and sending to device (including selecting tiles from osm, topo_nx, and others for one img file). But sometime in the last few months, I started getting errors where mapinstall wouldn't let me select tiles from osm and said there was a problem. I haven't figured this out.