That's interesting. I'm not sure what the problem is! haven't been able to replicate it. I did look in to it though.
From what I can tell, this might be a thing about cookies. Check that they are enabled, or that this page as an exception, or try a different browser.
I'm no web developer. If this doesn't help, or it's still occurring, tell me more about your browser and OS. I'm going to enable a download of the html file itself, which might also help.