Still playing with the Twenty Fourteen theme, as I said. Not using the featured-contents at all. By the way, something is going wrong. I have read about conflicts with plug-ins as Jetpack. It might be the size of the photos as well. It doesn’t matter for now, the blog is OK as it is and I will do further tests later.
In the meanwhile I have posted a question on the WP.org support forum. You never know. It’s full of great programmers and someone might solve the issue with a few checks.