When playing the downloaded file, I can only see a screenshot, but audio works fine. I've seen someone has had the problem before, but I still don't know what the solution is.
It seems that it might be the size of the file in regards to the resolution (even though all the other videos are at the same res and they don't have the same problem). I have opened the video in Windows Movie Maker and converted it again at a slightly lower resolution and it seems to have fixed it. Anyway, keep up with the amazing work you are doing guys. I really enjoy all of your tutorials. 
