In Pinboard 1.0.6 there was a file fitvids.js. It nicely grabbed iframes, put a div around it and made the video fit its container. This way the video is always fluid.
In Pimboard 1.1.12 the file is called now jquery.fitvids.js. This file is a bit changed. In a website the file is loaded in the frontend, but it does not do what it should do ie. grabbing iframes and make them fluid.
I think this problem has something to do with jQuery. But what?
False alarm. jquery.fitvids.js. does what it should do.