OSX 10.4.11 Model Name: mac pro Model Identifier: MacPro1,1 Processor Name: Dual-Core Intel Xeon Processor Speed: 2.66 GHz I insert Leopard Disk 10.5.6, click on the Install Button, get the "restart" screen, hit restart. Machine reboots but does not make it by the grey screen/apple logo. I've zapped pram, fixed permissions, run disk warrior, disk utiilities> verify disk. I've tried installing the newest version of APE. Nothing changes.. same thing... grey screen. HALP!