Why does my XNA Game Not Fill the Screen?

By default an XNA game is overlaid by the phone title bar. This takes up a row at the very top, so draws at 0,0 will not be properly visible. You can request the graphics device in your game to let you use the whole screen by setting its IsFullScreen property to true. The best place to do this is in the constructor for the game class:

public Game1()
{
    graphics = new GraphicsDeviceManager(this);

    // Make the game full screen
    graphics.IsFullScreen = true;

... rest of constructor here