http://www.divx.com
DivX 5.0.2 and DivX Pro 5.0.2 MPEG-4 video codec released.
What's new in DivX 5.02: here

I'd definately recommend the upgrade!

Apparantly there have been issues with non complaint mp4 video streams with the previous release which should now be addressed. Also a speed issue has been fixed.

Ruairi

I definately suggest you to download DivX in your recycle bin...
Switch to freedom, switch to XviD !!!

XviD - official site
Nic's XVID Binaries
uManiacs XviD binary place

Koepi's Page
http://www.roeder.goe.net/~koepi/

Both DivX and XviD create ISO MPEG-4 compliant video. I say that people should just use that which they feel is more comfortable to them (quality,usability).