I have a Compaq Persario AMD k62 with 128 ram. The system is using a Rage LT Pro AGP 2x and has the same problem. Smoke and transparent buildings work. Fog = white screen. File details are MACW4.DRV file version 4.10.2456. I also do not have the fog emulation button, (or just do not know where to look), but do have the latest version of Directx. Do this mean fog is hopeless. In other simulations, fog does not appear to be a problem.
I have seen a picture of fog in a post and it looks great!!! ANY CHANCE AT ALL FOR FOG?