Most people have been using the nimo codec package. I have a lot of problems while using it. So I did a search and found this site. http://www.3ivx.com/download/index.html
It fixes all most all the problems I had with video downloads. No more green screens, scrambeled video, I got sound on every movie now(wow), My videos are no longer up side down. This is not an ad just a little FYI because it worked for me.