Following Media Guide: Still stuck

I have been following this guide:
http://ubuntuforums.org/showthread.php?t=766683

its a sticky in this subforum. I can play videos on youtube, but when I try the "Test" site which is just apple.com/trailers, I can hear sound but not see the video. The video is a gray box saying the name of the file. I have followed the trouble link that he posted

http://ubuntuforums.org/showpost.php...&postcount=500

and did that as well - twice.

It still doesnt work. any ideas?

Tried doing the guide again, and still with the same problem. Can anyone help me?

Can anyone help me with this issue?