I could use some help here. I downloaded three .gpx files to the GPX folder on the Garmin device. I also created a GPX folder on the SD card and saved them there. When I disconnect the Zumo from my computer, or when I power it up next, I understand there's supposed to be a message that says it found new data. I never get that message. There are no new routes available in Where To? or in User Data. What am I doing wrong?