Rob Strong changed the variable format in the installer files.
https://bugzilla.mozilla.org/show_bug.cgi?id=399665 is the bug, and
http://bonsai.mozilla.org/cvsquery.cgi?treeid=default&module=all&branch=HEAD&branchtype=match&dir=mozilla%2Fbrowser%2Flocales%2Fen-US%2Finstaller&file=&filetype=match&who=&whotype=match&sortby=Date&hours=2&date=explicit&mindate=2007-10-24&maxdate=2007-10-25&cvsroot=%2Fcvsroot
is the changeset in bonsai.
He checked in a test that is run as part of the installer target to turn
all locales red that use the old syntax, too.
Axel