There are several 'flavor's of DivX - I am not intimately familiar with them.
I have, used many PAL DivX sources (I think 3, 4? and 5) to make NTSC DVD's. I honestly don't know what, if anything may have been different about the source files - they were downloads.
I don't think it's Divx exactly (although right before V4 came out, I e-mailed SoFo and that Vegas doesn't support Divx because it's a non-pro codec, the same thing that Adobe said about why mpeg-2's couldn't be loaded into Premiere 6 & earlier).
I belive it has to do with keyframes: Vegas uses keyframes to display the thumbnails. If it can't find a keyframe, the file won't load properly (not just divx, but mpg, wmv, etc). So, if you want Vegas to read Divx files, make sure they have EVERY frame as a keyframe.
That's true. I didn't want to edit DivX. The videos are in their final format. I wanted to use the script from JR to snap some frames from the videos...
If you're really hard up to deal with them, maybe transcode them to another format like DV using the free Panasonic DV CODEC or to HuffYUV, using VirtualDub. It's an intermediate step but it'd get you from A to B eventually.
After installing the latest ffdshow build you should be able to open DivX and XviD files with Vegas. Works for me, but Vegas won't open AC3 or VBR MP3 audio (I mean VBR MP3 in a DivX avi). CBR MP3 works fine. YMMV. http://athos.leffe.dnsalias.com/ffdshow-20040325.exe
Did you enable DivX 5 decoding in ffdshow's VFW Configuration?
Start Menu -> ffdshow -> VFW Configuration -> Decoder tab -> Codecs -> enable DivX 5 by clicking on 'disabled' and selecting 'libavcodec'.
I don't have to install anything other than the DivX 5 Pro package. I use DivX5 on the Vegas timeline all the time - every day. It most definitely works and it works really good - no different from DV. You might have to use a high bitrate - I use 1Mb or above and pretty tight keyframe distance of not more than 1-2 seconds.