This has been happening for a month now but could never figure out why. And it seemed to start happening sometime AFTER installing Leopard. Today i unplugged everything one by one and found out it's the keyboard waking the system. I have my keyboard plugged into the back and my mouse in the keyboard. I had the mouse plugged into the back and no keyboard hooked up and the system slept fine. I'm not sure what steps can be taken to remedy this problem. Any help would be greatly appreciated! Oh and i have an iMac G5 iSight i bought in January '06.