Mozilla fucked up RSS years ago when I filed a bug when they decided to remove valid CSS styles from RSS to install their own stylesheet. So I switched away from the piece-of-shit that is Firefox and never looked back. Mozilla has absolutely destroyed Firefox, once the king, now a slow, bloated sack of shite.
If you have a moment, read this, seriously: groups.google.com/…
Look at how the Firefox developers react. Long story short: they favor dumb users over the technical. The people who MADE Firefox are now the ones they are turning their backs on. When we move on (many have, to Chrome or Opera), who will force the non-techies to upgrade Firefox or install it at all on a new PC? No one. I never install FF anymore, I install Chrome. It's better in every way. Firefox takes almost 30 seconds from click to usable on my Windows 7 machine.
With their removal of the RSS icon, it's clear that those at the helm are looking for numbers, not the best experience. So eff 'em. I've moved on, you should too.