Some sites are not accessible with Windows 7

I can not access any sites that are in Real Age email. They are OK in Vista, but not in Windows 7. It is kind of puzzling, all settings in Firefox (my default browser) are identical in both OS. This is a sample site I can't open in Windows 7:

http://link.realage-mail.com/u.d?LYG...Fl8iki1Ac=7221

Any help would be appreciated.

Please don't double post - continued here:
http://discussions.virtualdr.com/sho...04#post1300504