I don see any graphics but I hear the sound on most activity screens. What is wrong?
You probably have Flash Player 2.0 instead of Flash Player 4.0 or higher installed on your computer. Go to the Site Requirements page to check your plug-ins. You should follow the link on that page to Macromedia (from http://www.macromedia.com) where you can download an updated version of Shockwave Player (which includes Flash Player).