I downloaded Firefox specifically b/c Ravelry said it would work better on it. And it does. I had some glitches with trying to upload stuff in IE. No problems when I use Firefox. And when you download it, it will transfer all your bookmarks from IE, which is fabulous.
Since the download, I've been using Firefox more & more over IE. Oddly enough, the only time I've had any kind of issue is when I'm on the KH forum (it sometimes loads a little slowly). But I'm really liking Firefox!