Thinkpad R61 spontaneous reboot while starting

[davidgurvich]

UPDATE: Posted solution in a different topic.

I've recently gotten 2 R61(8935-A47) in and wanted to practice installing OSX on these. The problem comes right after startup. I've been using iBoot and that has worked reasonably well for the base install on other laptops but not these.

The configuration is intel GMA965 graphics, Celeron 540 cpu. All the ports and peripherals seem to be working when I tested with a livecd. Snow Leopard starts the process, loading various kexts, and immediately reboots just before the splash screen. I've tried the following settings in various combinations with identical results and no other information:
GraphicsEnabler=yes/no
-x
-f
-v
arch=i386

Does anyone have any advice on how to continue?