Take a look at this Fiddle.
That's part of my login-page with the entire site stylesheet. This login form works brilliantly in Chrome, but in FireFox it, for some reason, freezes the username input after I've started writing the password, and when you remove focus from the password box, that's frozen too.
Does this happen with you? If yes, any idea why?
After Boris' answer my user-select stylus function now works perfectly and looks like this:
user-select()
user-select arguments
-webkit-user-select arguments
-o-user-select arguments
if arguments == 'none'
-moz-user-select -moz-none
else
-moz-user-select arguments
Which on usage renders to this:
user-select none:
user-select: none;
-webkit-user-select: none;
-o-user-select: none;
-moz-user-select: -moz-none;
user-select text:
user-select: text;
-webkit-user-select: text;
-o-user-select: text;
-moz-user-select: text;
-moz-user-select: none means nothing inside it is selectable, period. It doesn't matter what the styles of the things inside it are.
If you want to be able to override by styling descendants, you want -moz-user-select: -moz-none.