try this DSDT
is the 3.3 for 920 with your two GFX injected delete the EFI strings from the c.a.B.p and GraphicsEnabler=no (or delete this key).
If works ok if not it need to add more data in the injection like reg.data
let me know
YOU'RE THE BEST!!!!
it works perfectly!!! Nice, thanks, case closed, super duper, I'll mary you, maybe not, ok I will.
Now, while you were making me this super awesome DSDT, I tried something, just out of curiosity. I tried booting with my old patched DSDT from 10.5.8... and it worked. I had QE and CI, could play videos in QT... but I also had old problems back, that I had repaired with a few Kext on my 10.5.8 build. Few things like no shutdow and reboot, no wake after sleep, problems reading Data on second hard drive. It's all good with yours, but still, maybe you'll find something interresting in my old DSDT, maybe not: