Sign-up form no longer disappears on a slow connection
Opening Sign up while the page was still loading could close the form as you typed.
When the site loads, it checks whether you are signed in. On a slow connection, the answer could arrive after you had already opened Sign up, and the page then closed the form in the middle of typing. It now leaves a form you opened alone.
Also: the trailer on the front page closes only when you click outside it, not when you drag across the video and let go outside.