Trying to stream video from your host? Not working? The video starts but won't continue play from there? You're probably missing this tidbit in your .htaccess file:
AddType video/ogg .ogv
AddType audio/ogg .oga
Apply types as you add them yourself (like .mp4). This causes your server to add a Content-Type, which is required by the browser because otherwise, as you noticed, it won't play the video...
So, unable to get streaming html5 video? Hope this helps you :)