Night Lighting - Sunlight Glowing Over Horizon At Midnight

Ok I have searched through this forum, but didnt get my question answered. My Simulator never gets really dark. It seems it is stuck at dawn/Sunset. Always the orange belt on the Horizon. Is it already reported to ASOBO or is anyone else having this problem? Any suggestions to terminate it. It is no fun flying at night. I do not talk about the bright night sky, that is ugly either, but about the never ending Sunset.