Hi, I'm having a problem with my Intel iMac 20" (late 2006), two months ago my original HD failed and I had to change it. Last night my iMac was fine, but this morning when I woke up the screen was frozen, couldn't move or close anything. I turned off the power and on again and an icon of a folder with a question mark started blinking on my screen, started the iMac with my Leopard dvd but the HD didn't show up on the installation options or either on the disk utilities....