Just got the NAV+4 and was looking for any help on using the USB interface. The manual that comes with it is no help at all! 
I connected a USB thumb drive with some MP3 files on it to test, but all I get is a please wait message on the display.
Thanks!
I connected a USB thumb drive with some MP3 files on it to test, but all I get is a please wait message on the display.
Thanks!