I think this link will work:

moderator deleted a hyperlink to an unsupported version

I suggest, that while Mozilla is on a "rush to release updates faster than fixing bugs" kick, NO ONE should have "automatic updates" on. Go into "tools" and turn off that option, and NEVER agree to accept an update unless you know that things have been made compatible and that the bugs have been ironed out.

It's also wrong of them to release NON-beta copies, automatically, which cause incompatibility, every few weeks. That should only happen every year or two.

We need to ban together and quit installing their updates until they quit rushing them out too quickly.

@amlane -> Mozilla Firefox Portable Edition

• http://portableapps.com/apps/internet/firefox_portable

Install Firefox Portable 3.6.20 to use at that web site. It won't affect your current version of Firefox at all. Check and tell if its working.

@RonQ -> Starting with the release of Firefox 6, the previous versions of Firefox (4.0.x and 5.0.x) are no longer maintained with Security and Stability updates. Firefox 3.6 is the last previous Firefox version that is still being maintained.

Firefox versions 4.0.x 5.0.x contain Security vulnerabilities that are known and could be exploited by some websites to gain unauthorized access to information or to disrupt critical processing. Only the Latest version 6.0 and an Older version 3.6 of Firefox are secure against these known vulnerabilities.

• http://en.wikipedia.org/wiki/Vulnerability_%28computing%29#Vulnerability_consequences
• http://www.mozilla.org/security/known-vulnerabilities/firefox.html#firefox6