Video load problem...

[dogshootdog]

Hello, I really enjoy this software and look forward to learn all it's possibilities. I'm using it to build my final MA school work in photography. It's going to be sort of alternative erotic website for woman. Everything works fine, except for the video that sometimes play sound only and video starts to show after page refresh. Does anyone have any idea what's causing it? Here is the website: http://zvedava.cz/

Thanks a lot in advance, Jan.