Are you using the last version?
Wikimedia doesn't use CVS any more, but SVN at
http://svn.wikimedia.org/
extensions should be at
http://svn.wikimedia.org/viewvc/mediawiki/trunk/extensions/
This may also be due to the mixing of wiki-tables and html-tables syntax in
the template.
Brion recently changed the table behaviour, but as it shows well on
wikipedia (running from SVN), it may be not related....
Rather, I have *not* changed the behavior.
Enable tidy.
-- brion vibber (brion @