Chrome security indicators:

https://support.google.com/chrome/bin/answer.py?hl=en&answer=95617

Red x with slash through https:

The site uses SSL, but Google Chrome has detected either high-risk insecure content on the page or problems with the site’s certificate. Don’t enter sensitive information on this page. Invalid certificate or other serious https issues could indicate that someone is attempting to tamper with your connection to the site


So perhaps one of the non https links on the page is on google's watch list for "high risk" sites...