Delay playing video in Chrome

The clips linked to these icons should play in a shadowbox.js – however there is a delay of a minute or two before the clips start to play. It is as if they have lost their ‘faststart’ header information. They play no problem in Safari and Firefox on mac – haven’t tested other platforms. Any ideas or suggestions?

http://kropinski.net/portfolio/documentary/

https://wordpress.org/plugins/shadowbox-js/