I tried this and it does not work on the DNX525DAB. The device just recognizes the micro SD card and runs as usual with the maps from the SD card. It does not want to upgrade (ie copy the files in the internal memory). Btw, does the GarminDevice.xml must be on the card or should I delete it? Are there any other files that should be preset to "tell" the device that this is an update, not a map to run from SD card?