Right now, I am away from my computer so I haven't updated to 10.7.2 yet. I did take a look at your DSDT file and noticed that it is not an up to date version of the DSDT that I'd shared. Secondly, the easiest way to see if there is an overall problem with the DSDT or just with the GPU part is to remove Method (_DSM, 4, NotSerialized) from Device (VGA) and then either boot with -x or use GraphicEnabler=Yes.
Also, you can remove the GPU injector from my DSDT and try that file as well.
Let us know the result.
Thanks for the suggesting the removal of method from device (VGA). Now its booting properly. Haven't tried VGA Output/HDMI after removing the method. Hope this issue can be solved.