While troubleshooting another issue, I ran across this one.
When I try to send items in BC to the nuvi, I got an error I've never seen before:
"There was a problem communicating with nuvi2595 (Unit ID ....
An error occured while sending the following file(s):
gpx/gpxfile1128910744.gpx
gps/temp.gpx
[OK]"
Removing these files did not help. It was entirely by trial/error and narrowing down that I identified the cause: I had chosen a sitting dog symbol on a waypoint. Changing it to another symbol allowed the waypoint to transfer. The problem symbol is in the Dogs category, between Contacts and Letters categories.
