FS2004 FS Earth Tiles inverted results

I'm currently expand my horizont ;-) going east. I found some airfields which are currently not realized for FS2004 and not used active by real world aviation. These airfields are situation close to the sea / shore , so I like to use FSET to make a more or less photoreal ground and a reshaped coastline by using Google Earth (AreaKML.kml). Now I'm facing a strange effect, the results are inverted, means the coast line is correct, but it blends the land an not the sea-area... Does anyone has an idea ??? Thanks in advance