i bought a used Nuvi 765 off of EBay a while back. It worked very well, blue toothed just fine to my Sena headset, but the maps were out dated. So I plugged it into my PC with Garmin Map Manager and downloaded new maps with no issues (I had and SD card plugged into as well). Tried it out on a ride today and had an issue; on secondary roads the moving map showing the road I was riding would disappear, but it knew where it was because the correct road name would be displayed at the top of the screen. When I approached or turned on to major roads everything would work fine. Any ideas??