There is no way your org can use a Firefox version that is at least secure? (Such as ESR?) [http://www.mozilla.org/en-US/firefox/organizations/ http://www.mozilla.org/en-US/firefox/organizations/]

Unfortunately no. It is a National system that is certified by version, and for Firefox it is 3.6.25, and IE8.x

[http://www.mozilla.org/en-US/firefox/all-older.html Firefox 3.6.28] was the last security update for the the ancient 3.6 not the older 3.6.25. You could try using [https://addons.mozilla.org/en-US/firefox/addon/user-agent-switcher/ useragent switcher] to change the UA to the old 3.6.* or even do a manual override by setting '''general.useragent.override''' in '''about:config''' as a '''string''' and say the old 3.6.25 UA to fool site while being up to date security wise and not be [http://www.mozilla.org/security/known-vulnerabilities vulnerable] as 3.6.28 even is rather behind.