How do I convert FLIC files properly I need to open and convert old Autodesk Animator FLIC (.FLI) files (from MS DOS) into something more useful, like say AVI or even an image sequence. I realize both Motion and QuickTime "can" do this, but they mess up the films, probably because of a faulty decoder. 

I've already downloaded the UNIX app xnview, but it doesn't work well. While it can handle the format well, it can only store one frame at a time as a standalone picture, which is PAINFUL to do when there are usually several hundred frames in any given animation.
I don't know what you can do about converting the files....   However, if xnview will export the still frames to a folder, and if the files are sequentially numbered, QuickTime will be able to make a movie out of these images.  

Perhaps xnview can be scripted to export all of the still frames.

Will that work for you?