Can you indicate the exact message? On the login page, the certificate for www.target.com appears to be valid. Do you manage your account off a different domain, such as my.target.com or something else? Also, are you really running version 3.6.8? Firefox 3.6 has had numerous security updates and now stands at 3.6.18. Even though it might not help with this problem, you should update for your security. You can get the update using Help > Check for Updates or you can go to http://www.mozilla.com/firefox/all-older