@Blink, For your version you needed to change random_seed(0) to randomize().

Don't know if that will help with your framerate or not though.
Also there maybe a couple of other things that may not be compatable with your version. You may have to browse through the code and see if anything looks out of place.
It shouldn't take you long as there really isn't that much code to it. I wouldn't touch anything in the fog.fx though