When I drag in a section, container, or column it seems to automatically go to a zero or 1px height. In the video on basic layout this doesn't seem to be the case. It makes it hard to do something simple like drag a container into a section and I often have to look at the Navigator sidebar to make sense of where I am. I've attached a screen grab to try and explain what I'm seeing better.
The funny thing is when go in to the Navigator and click on another element it seems to temporarily fix the problem (in this case a row in the section above the section in question..