My hack is a homebuilt PC - ASUS PW5DE-Premium mobo, Pentium D 850 CPU, 4 GB RAM.

My original OSX install was done using XXX 10.5.2. This has been upgraded from 10.5.2 to 10.5.6 At that time, I had an ATI X300 card in the machine and I tried for 6 months to find a solution to get it working.

I swapped this out for a Quadro 1400 FX : device id 00ce
updated NVDANV40.kext, NVDAResman.kext, and NVinject.kext with the device id, installed EFI and using gfxtool generated the EFI string for this card and put it into my com.apple.Boot.plist

Rebooted and WHOO HOO - 1600x1200 full QE.

Fast forward a few months, my machine needs an enema so I have wiped one of my secondary disks and tried a brand new install of iPC 10.5.6 - installed the latest Chameleon 2 RC and EFI 10, and then applied the same changes to the kext's. I even went as far as to copy the kexts over from the working disk.
Cannot get QE back on this clean install of 10.5.6 - no way, no how

I am faced with going back to my 10.5.2 XXX disk and installing, then adding in all the updates back to 10.5.6.

Any ideas on how to get this working on a CLEAN install?