Uploading the wrong TYP file to the Nuvi or StreetPilot will cause the GPS to shutdown or restart by itself when you turn it on.
If you upload maps to the Nuvi/StreetPilot using MapSource, make sure you select Partial Custom Type installation (for Nuvi & StreetPilot) option during the installation of the SG-R & JOH-R MapSource Installer.
If you already ran the MapSource installer using the Full Custom Type installation, uninstall the map and make sure the C:/Garmin/SGJohMap folder is empty. Then install the map again but select Partial Custom Type installation (for Nuvi & StreetPilot) option.
download MS.TYP from my Public section, then delete the SGJOHMAP.TYP in the C:/Garmin/SGJohMap folder and copy the MS.TYP into the folder and rename the MS.TYP file to SGJOHMAP.TYP.