Today I tried my first screenshot. I'm running Windows 8.
Got the game windowed and pressed shift & printscreen. Normally this works fine on my pc.
The game gives me a fatal error rightaway and shuts down. There is a sort of double screenshot in the screenshot map, but it turned out green and purple. However when I pasted in paint it was a clear screenshot. So I dont know if this is a bug or just something my pc does. But I wanted to let you know.