Dude, do not boot with SnowOSX 3.5 because you will never successful with it, I though it was created for a specific motherboard.

I have mobo Asus P5LD2-VM Revision 1.03 which is similar to your mobo.
http://www.asus.com/product.aspx?P_I...RrN&templete=2

CPU Intel 630 3GHz 1 core HT SSE3 ( can't run Vanilla, a patched kernel is used )

I've installed successfully Leopard 10.5.8 and Snow Leopard 10.6.2 on a same Harddrive with PC EFI 10.5

I will post my complete success guide as soon as I finish my assignments

There is nothing called AHCI in yours and my mobo with Northbridge chipset ICH7 ( I believe that AHCI is available in ICH9 or 10, not sure, because I do not own such a new mobo like that ) but it doesn't mean that you can't install Snow Leopard.

I installed Leopard 10.5.6 first, I've used XXX 10.5.6 v2 follow this guide:
http://tgrounds.blogspot.com/2009/04...n-your-pc.html
The minor difference is that that guide uses iPC whereas I've used XXX

Then I followed this guide to install Snow Leopard
http://prasys.co.cc/2009/08/installi...ard-for-osx86/
Notes: you must learn how to create DSDT, use EFI String, select the right set of kexts for Snow Leopard

I dual boot Leopard and Snow Leopard by installing them into 2 partitions on the same Harddrive, boot loader is Chameleon + PC EFI 10.5, my HD is IDE and not SATA

As far as I know AHCI, IDE or SATA is not important, and yes, AHCI is the best choice. but we don't have and DON'T NEED AHCI

Then upgrade 10.6 to 10.6.2 using combo update downloaded from Apple

Good luck