I have a DivX 3.11 file that I want to split into 3 parts. How do I do this?

I have seen the how to guide on how to do it with VirtualDub, but when I try that, the following happens:

I go through the loading process etc. then when I move the slide bar across to the point where I want to cut, the end of the movie show up on the preview screen, even though I have the slide bar only a third of the way across.

I have also read somewhere to stay away from AVI Chopper, as it causes alot of audio sync errors.

Thaks in advance.