System: Mandriva 2007 Spring
Receiver: Garmin etrex vista hcx
Download tools: garble, gpsbabel
Symptoms: Waypoint downloading (from receiver to PC) is consistently successful. Downloading of small tracks also successful. Downloading of normal-sized tracks (hundreds of points) fails often, causes timeouts, only succeeds maybe one time out of 10 or maybe worse. When it's finally successful, data is ok.
Workaround: Blacklisted garmin_gps in system, used the usb: device in gpsbabel instead of /dev/ttyUSB0. Then all downloading is consistently successful.