I have updated the maps on the Mac & Zumo 660 to 2015.20 (on the SD Card), with 2014.10 remaining on the Zumo internal memory.
When i plot a simple circular route on the Mac and transfer it to the Zumo, the route is being produced with lots of spikes in it.
I have no idea why, and I have never had the problem before. I have sent the route to the Zumo internal memory, not the SD card, by the way.
Can anyone tell me what I am doing wrong please?