Google Earth Plugin 的简单 KML 层，ScreenOverlay 显示如预期（徽标在右下方）：
http://build.livegallup.com/community/trail-system/?tx_trailsystem_trailsystem[trail]=38&tx_trailsystem_trailsystem[trailSystem]=6&tx_trailsystem_trailsystem[action]=showearth&tx_trailsystem_trailsystem[controller]=Trail
谷歌地图几乎相同的 KML ......没有 ScreenOverlay（？？？）：
http://build.livegallup.com/community/trail-system/?tx_trailsystem_trailsystem[trail]=38&tx_trailsystem_trailsystem[trailSystem]=6&tx_trailsystem_trailsystem[action]=show&tx_trailsystem_trailsystem[controller]=Trail