If my interpretation of Jim Hu's question
("[Mediawiki-l] IE7
extension textarea problem - just me? css?" dd. 30-Nov) is correct,
he's probably suffering the same problem.
If that is expected behaviour for IE, and given that the &nbs; does
not screw up the display of the other browsers, would it make sense
for MediaWiki to make non-breaking spaces the default? Or is he
right in that we can/should fix this ourselves via the css?
The default what? The default for a parameter if none is specified is
a literal {{{1}}} or similar (which will display in any browser, but
isn't really desirable). The default of a space was entered into the
wikitext manually, just as the default of a non-breaking space was.