User blog comment:Kirkburn/Technical Update: October 1, 2013/@comment-1997588-20131003134418/@comment-452-20131003151902

That problem appears to be caused by a "width: 2em;" inline style in the span around the link.

I'm not seeing this problem occurring on other wikis, and I can't see where that style is being applied, but it's a complex template, so hopefully someone with more experience with the template will be able to work it out.

I notice that the navbox is using the old "collapsible" class rather than the built-in "mw-collapsible", so maybe that's the cause.

update: After typing that, was going to link you to http://dev.wikia.com/wiki/ShowHide and point out that it's deprecated, but first went to check http://sims.wikia.com/wiki/MediaWiki:Common.js to make sure you were indeed using it, but you're not.

Button.style.width = "2em"; is your problem.

edit: nevermind, I was 4 mins late.