I have the same problem that AresMars had, and it will solve if I allow "Private Header Information" in third-party Cookies. But that pose a security problem for me. According to my Firewall help-file - the removal of "Private Header Information"
Prevents your IP address, your workstation name, login name, or other personal information from being transferred to third-party sources.
And imho SinoDefence.com should not demand that their users have to open up their firewalls in order to view the site.
BTW this must be a relatively new thing, because I have used the same firewall for at least 3 years and I have never encountered this before.