I’ve had this same problem before and it was never resolved. When I switched from Google Chrome to Safari, it seemed go away and was a work around. Now both browsers do the same things.
When I try to move images around in columns, elements start to disappear. Eventually everything on the page will be gone expect for the header and footer. I get the message “This element could not render due to invalid markup. You may have unclosed html tags in your content.
This was my previous topic.