VideoJS: audio but no video

So I have been converting videos to mp4 and it is working fine (I can download the file and play it in wmp without a hitch) but when I try to use the html5 video tag by itself or with video js (videojs.com) enabled, the video only plays audio. It doesn't play any video.

What could I possibly be doing wrong?

Video: http://www.xonicgames.com/user/uploads/videos/6360.mp4
JS: http://xonicgames.com/video/?i=6

Thanks

Not all of the browsers support all of the video/audio codecs ... it depends on the browser and its version and has been subject to rapid changes. For example, last time I checked Firefox did not support the H.264 in MP4 container.

So throughout the internet it is recommended to serve the video in different codec formats and let the browser decide which one to choose.