Though I do not want to disbute your saying, I have quite some different experience. Many times that I download movies with just one host and have no problem at all (although it needs some time depending on the hosts internet connection -modem, cable, etc.). From a couple hundred I just had one which wasn't that good of a quality. Also with the porn thing, happened also only once to me, and another time the movie was actually different to the title.

Regarding the Divx, here would be a link to the free download: http://www.divx.com/divx/play/player/

However, you could also try the VLC player (often recommended here in the forum): http://www.videolan.org/vlc/

Cheers
Mario