Zombie-F,
I'm a FOG fanatic and I'd say the only music that isn't on the soundtrack is the electronic elongated cords when the fog first rolls in and kills the three men on the boat in the beginning (and in the doctor's office) and the cool electronic organ music as they ride up to the church to find Fr. Malone early on in the film. It's missed too. I hate when for some reason cues are left off of a soundtrack.
The BEST track from BIG TROUBLE IN LITTLE CHINA during the airport kidnapping is nowhere to be seen on that soundtrack. And the hospital scene in HALLOWEEN 3 is omitted as well.