Garmin map problem
 

My Garmin 236 is set to have the map course of the boat at the top. I used
to have it set to have north at the top. Since changing, the Garmin map
seems to refresh every few seconds even if the waypoint is ten miles away
and the map adjusted out to show the entire ten miles. This causes the route
track to jump around too much. Is there a way to stop it from refreshing so
often?

Thanks,

John