You know, this is why I hate firefox now.
Their quality standards are slipping, seriously. This "rapid release schedule" is killing firefox.
First of all, no enterprise would use their "rapid release" products. A new version every 6 weeks? The IT people will fight to the death to block that.
Secondly, their quality is slipping. Bugs slip through, performance is bad, etc.
If you want to use firefox, consider the long term support version:
http://www.mozilla.org/en-US/firefox/organizations/
Say what you want about IE, Microsoft does continuously support their browsers. Even IE6 is still getting patches and fixes (support is ending in 2014 I believe), whereas firefox 15 has been abandoned......