The latest version of Chrome will now show a red 'X' in the HTTPS header for your site in the address bar if the site uses the older SHA-1 hashing method for the certificate. It happens regardless of the key length for the site (standard is 128-bit). The issue is exclusive to Chrome, and it doesn't appear that it will ever be fixed, as they're trying to move vendors to using SHA-2.
The only option I've found is to upgrade existing certs to SHA-2, or ask your users to move to a different web browser. Some cert vendors will allow you to do this through the web portal on their sites, while others prompt a phone call for each and every cert you change.