You can ignore (CSS) errors in the Tools > Error Console.<br /> Those errors are only useful if you develop websites and want to check the HTML/CSS and JavaScript code for errors.<br /> Most errors are code for other browsers like IE or browsers on other platforms or just typos or the result of bad coding. The message about CVE-2009-3555 is meant for webmasters to make them aware that they need to fix their servers and visitors like you can ignore that warning.<br /> Firefox 3.6 versions can detect such a misconfiguration and displays a warning in the "Tools > Error Console".<br /> * http://wiki.mozilla.org/Security:Renegotiation ---- What kind of problems do you have? * http://kb.mozillazine.org/Error_loading_websites * http://kb.mozillazine.org/Error_loading_secure_sites * http://kb.mozillazine.org/SSL_is_disabled