The correct firmware is this:
nuvi 54 is a re-badged 52 [HWID 1613] not a re-badged 50 [HWID 1350]. Right clicking on the above page and selecting 'View Source' or similar from the context menu opens a new window with this in it:Code:http://www8.garmin.com/support/download_details.jsp?id=5937
Use that to make your cure fw and it will load ok.Code:http://download.garmin.com/software/nuvix2andx4_GCDFile__400.gcd