This is probably a simple solution, but I'm still having problems.
I have an animation sequence (roughly 1miin long), involving particles and Fume FX. I want to start it off real time, then go slow. I plan on rendering 1 segment in real time and another at a fraction of the speed and edit in post, but whenever I adjust the Frame Per Second in the Time Config or render settings (avi/Mov), the particles go wild and Fume Fx is not affected. Is this something that I have to animate within 3ds or does my plan of rendering 2 segments hold up? Your help would be much appreciated.

In the time settings, (The icon next to the box with the frame input), there is a button that say's "Re-Scale Time". Try using this, its usually pretty effective.