Lots of various media things don't work in Firefox for me. For example, if I'm on a site, like even a .Mac webpage where someone has posted a bunch of photos, and say I'm looking at a particular photo and click on the next photo to try and view it, it won't. Media files generally don't load, like YouTube.
I like Safari, but certain sites I went to normally didn't work. That was maybe 6 months ago. I started with Firefox, switched to Safari, back to Firefox, and because of my problems with Firefox, I am trying Camino, and this baby works on every site. I don't care if it takes an extra 1 second to load up. It's insignificant, and if i can get onto the sites I want, then super. 🙂