Need your recommendations for a slow machine.

Hi, I am trying to optimize DivX 5 playback for a slow machine.

Luckily I have bumped into BSplayer, which I heard helps a lot (haven't had the chance to try it yet)

Right now with the Divx Player, scenes with a lot of motion are extremely choppy; post processing quality is set to minimum, as well as effects.

Lots of free ram, minimal backgroudn processes, no distributed computing projects.

Resolution is 640x480 at 16bit colour.

Anyways, does anyone have any suggestions?
Thanks!