User blog comment:Kirkburn/Technical Update: May 14, 2013/@comment-4625170-20130516100856

I think there is a bug where when you add a category to a page using the bar at the bottom, any infobox on the page gets decomposed into the template code. Hard to explain, look here http://deathnote.wikia.com/index.php?title=Confluence_%28volume%29&diff=30241&oldid=30116