I'm trying to get the standard wpGallery running in my post. I followed this tutorial.

But I can't get it working. This is what my editor shows while editing a page:

But at the front-end nothing displays.. I've edited the TwentyTwelve theme to get a custom layout so I delete some things in the page.php, content.php and several files.

Someone familiair with this problem or knows what I can do to make it work?

Thanks!