Updated to 3.3.1 and the password cannot be copied now, it just disappears. Theme comments.php was already set originally with correct code to work and it was working prior to the upgrade to 3.3.1.
I searched the form and couldn't find the specific issue related to what is going on. I tried Chrome and Firefox and get the same issue with not being able to copy the password. When I type it in exactly, I get the error: Error 1: Click back and type in the password.
Here's a link to a comment area: http://www.peerlesstreefarm.com/2011/04/trees-video-pictures/