Yes i took a glance of your posts and replies at insanelymac before i posted here for the first time. In my opinion its the bios fault why you cant boot.
Yes, disk(s) in sata->ahci mode can help you reach the installer and install os-x on your hdd before you install driver for your chipset so you can set hdd in native->ide mode later, or keep ahci mode. But you dont have such an issue here, cause you are not reaching the installer at all. I have SB600 chipset and ahci mode is needed to install OSX, you are right about that. But when it comes to it, you can inject the driver into dvd installation and boot with it (if its not possible to switch to ahci).
We (i mean you) have a very delicate situation here. I still blame the bios for it, maybe some of ACPI seetings in it.

** From my personal experience, i have one laptop which is totally unsupported. I am running Tiger on it. It doesnt support any newer efi bootloader even with older (like efi 5) it sometimes boot and sometimes just restarts itself. Its all because of the BIOS. I switched to tiger cause leopard is a bit more demanding and my gfx is also unsupported (like i said totally unsupported) so running in vesa 3.0 not much of fun. After all it looks to me like pushing an elephant into matchbox, it simply won't go, more problems than a real fun, not even for everyday easy tasks like browsing internet, email, etc. Its intel dualcore (like the first macbooks) so theoretically i could run vanilla kernel, Via chipset is supported, but bios is blocking me. So i switched it back to its default vista installation and my wife is enjoying it now playing Zootycoon and Age of Empires 1 ;-)

Maybe some of the other guys could come up with some idea how you can solve your issue, if its possible. What i would do if i was you, is stick to your desktop box. It looks to me like capable of running vanilla and enjoy all the benefits of 100% mac.

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