Non-breaking space in all its forms should be rendered as
(working with all browsers I'm aware of) or (issues with
one old browser if there are two or more adjacent ).
Under absolutely no circumstances can /   /
or the corresponding UTF-8 be rendered as mere SP, that causes
havoc. This appears to be relatively new (2006-04-13 maybe?).
I've tested it elsewhere with action=render, it's no skin issue.