Likewise I was having issues with transferring routes from my iMac to my Zumo XT.
Option One:
Copying and pasting the .gpx file using Android file transfer didn't work for me, the Zumo didn't report a new route being imported or show it in my saved routes. (Perhaps you have to put this route in a specific folder?)
Option Two:
Use the Export function, failed, got the following error:
"Device could not be found or written to. Please confirm that the device is actually connected and working properly"
It was and is, but didn't transfer!
Option Three:
Save as as .gpx 1.0 (track. POI), find saved .gpx file, email to myself, open email on iPhone, Send to Garmin Drive, Open Zumo XT, import new track, convert track to route.
This works but when you go to access the route it says "Editing this trip will discard the current route settings and calculate a standard route"
It seems to give you a good route but it's lost the waypoints, however it is an accurate route.
Option Four:
Export as .gpx 1.0 (route, track, POI), (Then follow the same procedure of email to yourself, Garmin Drive etc) when imported it recalculates the route but does seem to retain the route chosen and the waypoints.
Question:
If I change waypoints to shaping points will it still 'force the Zumo to pick a route I've plotted (as long as I add enough points)?
Note: I also tried taking it back into Basecamp and transferring to the Zumo but this gave me weird and crazy routes. I think this might have been a mismatch between the maps as I've just been able to transfer the map to my iMac. This ability had been missing until recently from Garmin Express.
