It disappears with even the slightest movement down the screen. Most people are using the scroll button on a mouse and not the bar at the side. For anyone new to the site this is going to be an issue. And not everybody logs in immediately upon coming to the site. I like to browse and if I get a notice about I MOC I go check it out. At that point, if I wish to comment, there is no visible way to log in. Anyone new or unfamiliar with this new setup is going to get very frustrated VERY quickly. I know I am.