We have added a new feature that allows you to select your "default community," and you are prompted to do so upon initial login. In short, this applies your preferred community theme when you are on general areas of the site (such as your inbox). This setting controls the look and feel of the site, and enables us to support multiple communities on this single platform. It also allows the mega-nav for your community to persist, making it easier for you to navigate around the site. You can always change your default community by hitting the drop-down next to your name, selecting "Edit Profile," and choosing the "Your Profile" tab.