Happy breaking ^^
Skycube pic made with Terragen 0.9. Looking upwards doesn't look this different. I don't see any effects like in your shot.
Try with one of the skycubes that comes with Gamestudio. When you still have this odd artifacts then it is a Gamestudio settings thingie. When it works fine with them then you have a problem with the skycube you have made with Terragen.