Hmm...
Ok, I have
Divx Codec 5.0.2 pro bundle
Divx Codec 5.0.3 pro bundle
and another just says Divx Pro Codec

Mpeg layer 3 codec FHG Radium v1.263

PICVideo Codecs
and XviD MPEG-4 codec

The AVI i'm trying to view has DivX listed as it's video compression.

I tried watching it in BS Player, DivX, and windows media player. All blocky