It works just fine when it is booted up, and using discs. But any time that I boot from a disc (such as when I tried to upgrade to Leopard, but was too scared to let it finish because of how bad it was scratching my disc) it scratches the BADLY. It got to the point that since it only does it when booted up from a disc, I used Disc utility to put Leopard on my iPod and install it from there. These scratches happen going from the middle of the disc directly to the outer edge. Why is this happening, and is there anything that I can do about it?