First i suspected it would be result of changes in #684, but looks like it's
something other(, too)
Look at this url:
http://jadesukka.homelinux.org:8180/mediawiki15d/index.php/Bug684 (latest clean
cvs at the moment)
I have two extensions which use tags oo and ooo.
Probably you see better yourself what's wrong than I trying to explain it.
May also be worth of checking if related to php warning in
http://jadesukka.homelinux.org:8180/mediawiki15d/index.php/Nuka-Wiki_unknown_01
Version: 1.5.x
Severity: major
URL: http://jadesukka.homelinux.org:8180/mediawiki15d/index.php/Bug684