OK, I am one of the guys who have the unfortunate restart/panic problem. If you don't know what it is, here's more explanation: when I boot the setup DVD natively, I got a screen saying (in multiple languages): You need to restart your computer, blablabla... then I dig further, and use verbose mode, I found some thing like panic or kernel trap, waiting for debugger stuff... I tried the VMWare installation, which turn out to be fine. But once I start natively, the problem comes out again! So I took a closer look at the verbose mode messages, and found that the module causing the problem was HDAudio driver. So I went into BIOS, and disabled the on-board audio, and boom! I got passed the startup screen. Later in osx86, I modified my AppleAzalia driver to recognize my realtek audio chip, and enabled on-board audio again, it is now working flawlessly!
P4 3.0G HT
1.5G DDR2 RAM
osx86 on a 160G SATA disk
So if you got stuck in the kernel panic problem, take a closer look at the error message, try to disable some component or boot into single mode to temporarily remove the problematic kext. Hope this could help!