The message about CVE-2009-3555 is meant for webmasters to make them aware that they need to fix their servers.<br /> Firefox 3.6 versions can detect such a misconfiguration and displays a warning in the "Tools > Error Console". * http://wiki.mozilla.org/Security:Renegotiation If those buttons do not work when you click them that that has another cause. Start Firefox in [[Safe Mode]] to check if one of the add-ons is causing the problem (switch to the DEFAULT theme: Tools > Add-ons > Themes). * Don't make any changes on the Safe mode start window. See: * [[Troubleshooting extensions and themes]] * [[Troubleshooting plugins]]