I thought DivX was straight MPEG4? Maybe not though, which would explain the codec requirement. I'm assuming the name came from the short lived DVD medium where you watched the movie once, and it became disabled after 24hrs. I'd bet you're right RaoulDuke.
There's an article that explains it pretty well on Tom's Hardware. You'll have to find it yourself though, cause I lub AT
Straight MPEG is the way to go for VCD's. I'm only interested in DivX cause it'll be a convienent way to take my DVD collection to school with me.