Firebird has been nothing but spectacular for me. I use it on 2000 pro, win xp, win xp tablet, 2000 advanced server, and 2003 advanced server. No problems (though the smilies not working on the message board afflicts me as well, but that's no biggie).
Frosty, here's a little feature you will learn to be unable to live without. If you hit the / key and start typing a word, it is the equivalent of, in internet explorer, clicking Edit, Find on this page, and typing in a word to search. It's brilliant in web research.