420 rider suddenly wont import routes
had no problem doing up routes on the computer and then via usb importing them onto the device.
then suddenly I get an error message that "none of the selected routes could be imported"
the file goes onto the device ok and is visable. its when I "select routes to import" it refuses and the error message appears.
I have reset the device and tried with files that did work but to no avail.
any ideas ?