Well at first I had like 250GB of free space in my D:\ drive. Started FO3, played like an hour and stopped. I was randomly clicking folders when I saw only 50GB space left....wat?

I didn't find any TEMP folders that would by any means fill space.
I'm on Win7 32bit. Next thing I'm probably gonna do is sum up every folder and see what actually happened.
Anyone of you ever experienced this?