I'm sure what we are seeing is some non-standard wiring in their USB cable; something like a resistor between some of the leads.
Take a look at
http://forums.gpsreview.net/viewtopic.php?t=19630 especially
http://forums.gpsreview.net/viewtopi...=149425#149425 and also
http://forums.gpsreview.net/viewtopic.php?t=9346 for what was needed for a Garmin GPS cable.
I'm not saying this IS what is needed; just a link to what has worked for other devices.