Workaround for issues #4 and #6

GraphicsMode.Default used to be set to
(DisplayDevice.Default.BitsPerPixel, 16, 0, 0, 0, 2, false) for improved
compatibility with older systems. However, this appears to be causing
issues with specific modern GPUs. Switch the default mode to (32, 24, 8)
until a more proper solution can be found.