Where on the worldwide network are you seeing such messages (e.g. country, city)? Does the error message appear for Graph API requests (admin interface) or for Facebook JavaScript SDK calls (website front-end)?
Facebook bundles Mozilla Firefox’s root certificates to address some issues with IIS servers. The abstractions of WordPress HTTP libraries make SSL certificate bundle overrides more difficult than a direct HTTP system such as cURL. Your site seems to be running IIS 7.5.
I’m getting the warning front and back. I’ve also noticed in Chrome it doesn’t show the number of likes. In IE if I do not select Show All Content, again the Likes do not appear.
My site runs on Windows Server 2008 R2 64. I’m a MS Partner and developer on the MS platform since 1995, but I’m new to WP and php.
Android says:
This Certificate is not from a trusted authority.
Common Name: s-static.ak.facebook.com
Organization: s-static.ak.facebook.com
Organizational Unit: s-static.ak.facebook.com
Issued by:
Cybertrust Public SureServer SV CA
Organization: Cyvertrust Inc
Organizational Unit: (blank)
Validity:
Issued On: 3/1/2013
Expires on: 3/1/2014