I wanted to change my avatar, but not my profile picture. I removed the avatar picture, then browsed to the new one I wanted. But when I said update, I was taken to the sizing screen (can't remember its name) and I saw that both my avatar and profile had been changed. I didn't see any way to cancel the change on this page. So then I had to go back and change my profile picture to what I had originally.This time, I was able to change my profile picture without changing my avatar. So I think this is just a plain old bug.

I'm using Firefox 3.0.14 on a Windows XP machine.