It's the current feeding frenzy. Sorry about that. There's not much to do other than to try downloading later today, or tomorrow.
Our server can handle about 50 simultaneous video downloads on top of the rest of the site's traffic, but when people start to try and download multiple files simultaneously the server starts to sag.
We ask people not to do this, but some people are in a hurry.
It'll sort itself out in the next few days.
Thanks for your patience.
Michael