Hello to the forum. I'm stumped. Just used my eTrex last week then two days ago Mapsource can't find it. Tried different USB ports, downloaded the USB Drivers again, restarted my computer, swapped the cable. It's the Interface. Can't change the setting to "USB Garmin Data Format" What could cause this problem? Hardware? Software? Sure hope I don't have to send it back to Garmin. Appreciate any help you folks can give to me. Otherwise, guess I'll have to sit on the phone with Garmin tomorrow morning. Thanks, Bill PS My GPS-V unit talks with Mapsource fine. Different cable but Windows autodetects it on COM port 5 and hooks up. Used it to load a waypoint so I could drive to the trailhead but no way was I going to carry that big guy on my run. At least I know Mapsource hasn't gone weird.