This might be a problem with the parent classes here, but on the comments listing page (and authors, and revisions...), when using the "show X items per page" box, we get an extra &title= tacked on the end of the URL.
Version: unspecified
Severity: major
URL: http://www.mediawiki.org/wiki/Special:Code/MediaWiki/comments?limit=500&title=Special%3ACode%2FMediaWiki%2Fcomments