when starting up firefox, our fortigate firewall has started issuing a warning.. "Secure connection failed- s-static.ak.fbcdn.net:443 uses of invalid security certificate. The certificate is not trusted because it is self signed. The certificate is valid for FGT50B3G10615174 Fortinet. (Error code: sec_errror_ca_cert_invalid). This could be a problem with the server's configuration or it could be someone trying to impersonate the server. If you have connected to the server successfully i the past the error may be temporary and you can try it again later." This error is coming up on more than one computer when going into Firefox.