I get a SHA256 certificate for that site. What user agent are you using? Is there some kind of middlebox on your network, or do you use AV software that intercepts TLS connections?
No I'm not using anything that intercepts TLS connections.
EDIT: It's fixed now, `sudo apt-get install libnss3-1d`.
http://askubuntu.com/questions/880695/neterr-cert-weak-signa...