Getting AHCI after clean install--won't recognize drivers

[nickr]

I did a clean install of XPPro with BIOS in compatibility mode. Then I installed the Intel Matrix Storage Manager (after the Intel Chipset update) and then rebooted switching BIOS to AHCI. The computer recognized the hardware and asked for drivers, but when I directed it to the IMSM location, it could not find any satisfactory drivers.

So I ran the "prepare install.cmd" again and tried it again. But now I always get a blue screen when I try booting from AHCI.

The thing that annoys me is that I have a perpetual "USB" icon in my systray recognizing the DVD burner as a plug and play. But in AHCI mode, this icon goes away.

Anybody know a fix for this. (I've searched every post I can find and am hoping there's some new info some has).