Weird top margin appers on some templates

Hello,

I get this weird ~10px margin to my whole page. It only happens when I’m using a custom template. For example I’m trying to render my front page a bit differently from other pages, so I created a page-home.php template and pasted the code from the page.php to it. Even if the code is exactly the same (expect the <?php /* Template Name: Page home */ ?> in the beginning) this margin issue appears. Where is it coming from??

All help appreciated! Thanks.