Hi,
After searching through the forums I thought I should not start a new thread but post here. I get exactly the same problem, it gets to starting darwin and my PC just restarts.
It happens with iPC OSx86 10.5.6 Universal PPF5 Final.
I have:
cpu - intel core 2 duo e4600,
mb - foxconn g33m-s (chipset: intel g33, southbridge 82801IR (ICH9R))
2048MB DDR
integrated graphics as the above mentioned mb chipset says,
two sata hdds

Hope this serves enough to get some help, if not, please tell me where to look for.