In current development releases of Google Chrome (seen by myself on Linux, but the bug causing it should be present across all operating systems), the wiki displays incorrectly, with the sidebar (with navigation links and such) appearing after the main content, rather than by its side. To my knowledge, Safari is not currently affected.
MediaWiki and Wikipedia appear to have resolved the bug by deleting the lines from skins/common/wikibits.js (lines 94 and 95, in your copy, at least) which include the file, removing that file from use at all. I believe this change has probably gone into the newest MediaWiki, but I don't know if any releases have been made containing it yet. In the meantime, deleting everything in KHTMLFixes.css in the custom skin (with the file deleted once newer MediaWiki no longer uses it anyway) might be an easier solution, and eventually needed anyway if MediaWiki updates to avoid leaving unused files around.
https://bugs.webkit.org/show_bug.cgi?id=28350 - The Webkit bug report for the issue; the accepted solution to point, certainly once Wikipedia fixed it, has been "get sites to upgrade/fix the bug", although a MediaWiki-specific hack appears to be being discussed.