Wikimedia Bugzilla is closed!

I've isolated it to this rule in main-rtl.css: 

#footer #footer-places {
	float: right;
}

If it's not floated, problem goes away. Weird, and probably not the right way to fix it, but that's the simplest solution I've found thus far. Now, I'm not sure how to tell CSS janus to allow a float in LTR but remove it in RTL....

Fixed in r62030. Could be improved upon, since footer elements are not rendering exactly the same in IE7 as other browsers, but the main issue is addressed and the page is now rendering at the correct width in all browsers.