I open my .gpx file in Google Earth. It is a four month long journey across the United States. When I try to display the track in Google Earth it begins with an arrow and by highlighting the route I followed, but then begins erasing it before the entire route is displayed. Also, at a certain point the arrow continues along the route but no highlight follows it. How can I get a highlight to follow the arrow the entire route traveled without any of it disappearing, so I can see my entire four month journey displayed by and at the end of playback?