Facebook broken over v6?

It's affecting anyone running dual stack, as the server responds, hangs, times
out and then it tries again on v6. At least in the latest FF and Safari
browsers, I've not tried chrome.

I've cc'd this over to Nanog, as I've not seen anything about it there, and
I'm sure others are seeing it.

www.v6.facebook.com works fine as a workaround for the time being.