While it is so much better than Internet Explorer in many ways, firefox has been being a brat to me for a while now.
I've installed Opera, and just LOOOVE it! I can comment on blogs that i couldn't before, and they have lots of very cute (probably just that) widgets. I'm thinking about uninstalling tweetdeck because Opera has it's own twitter widget that actually works for me- unlike the add-on for firefox. it's not as nice looking and customizable as tweetdeck, but i'm sure it takes up less memory.
So far I've been able to play scrabble on pogo with out freezing or having to close everything else out, and Opera also has a pandora widget, so i don't have to keep an extra tab open to jam!
My only one qualms with it arethe bookmarks import- bookmarks aren't as easy to get to in this browser, but, I'm sure it's just seeming that way because it's new, and i'm used to a different format and the fact that there is no spell checker built into the browser. Firefox underlines and suggests correct spelling for words typed in on pretty much any form in the browser. So, you're going to be seeing more typos, but also a less frustrated me =-p