I've been using the Mosaic screen saver ever since I upgraded to Leopard. It has been working flawlessly. Yesterday, I finally received my Nvidia Geforce 8800GT graphics card for my Mac Pro. I installed the card without any problems and everything works fine except for the mosaic screensaver. As the image zooms out to create the next image, the screen flashes white, just as it is about to dissolve to the image it is creating. Could this be a problem with the Nvidia card or is there something else that may a been corrupted. Anyone have any suggestions or ideas.