well, today I tried a different demo (double the size, ~1 MB), and... first it put more than 30 GB on my disk and then it didnt even make the AVI
I hope you can fix that.
Oh, btw, this time it opened the game in Fullscreen (1280x1024) first, and then I went in the settings and changed it to 640x480, so that probably explains the amount of data. But why did it open in fullscreen?