I have the exact same problem with my laptop LCD not working, though my external monitor works great with QE/CI enabled. Using the "GraphicsEnabler=Yes" under Chameleon does work better than any of the injectors I tried, at least as far as as far as properly detecting my card (they did all enable QE/CI though). It's what I use and it recognizes my card by name which none of the injectors did.
I have a Tecra M4-S435 Tablet with a 1.73 Pentium M, not the duo like you do. I am running 10.5.8 as Snow just would not work properly. It would install and run, but all the dates and times were in negative values not sure what that means.
I would just like to get my internal LCD working, don't really care about the touch screen. But it would be cool. Everything else except Intel wireless (known issue) works perfectly on my Tecra, even sleep. I started a thread a couple weeks ago I think..lots of views, but no responses. At least someone is responding to yours. I will be watching this thread with great interest. If I make any headway, I will post here. Good luck!

Also, you might try IAtkos 10.5.7, that's what I used and then updated to 10.5.8 by downloading 10.5.8 update and running it from my machine. Worked without a glitch (Do not download combo update and DO NOT update through Apple's software update)

gkmacdev

Model Name: MacBook Pro
Model Identifier: MacBookPro5,1
Processor Speed: 1.73 GHz
Number Of Processors: 1
Total Number Of Cores: 1
L2 Cache: 2 MB
Memory: 2 GB
Bus Speed: 533 MHz

GeForce Go 6600 TE/6200 TE:
Chipset Model: GeForce Go 6600 TE/6200 TE
Type: Display
Bus: PCIe
PCIe Lane Width: x16
VRAM (Total): 64 MB
Vendor: NVIDIA (0x10de)
Device ID: 0x0146
Revision ID: 0x00a2
ROM Revision: xx.xx.xx - internal
Displays:
Display Connector:
Status: No Display Connected
COMPAQ 7550:
Resolution: 1344 x 1008 @ 75 Hz
Depth: 32-Bit Color
Core Image: Hardware Accelerated
Main Display: Yes
Mirror: Off
Online: Yes
Quartz Extreme: Supported
Rotation: Supported
QuartzGL: Supported