A recently infobox template is adding a <br /> tag after itself when included on a page on our wiki, resulting in the first line of an article being blank when included at the top of the page. For example, compare the top of the infobox to the top of the first line: http://www.svrwiki.com/GWR_2857_Heavy_Goods_Loco
This doesn't occur on other wikis with infoboxes. I can't pin down where the line break is originating from - as far as I can see, Mediawiki adds <p> tags when two or more new lines exist, not <br />. My main suspicion would be some dodgy CSS, but that shouldn't be adding HTML. Any thoughts?