Well, WAHa, you can't believe everything you read... I'm telling you, I just install the DivX codec files, and the times when I come across an AVI file that QuickTime Player doesn't play or won't play properly are few and far between. It won't kill ya to just try it...

As for WMV3 in AVI... Have you tried just giving the AVI file a .wmv extension? I seem to recall having a similar problem in the past and successfully fooling WMP by doing that.