I had the same issue. I took a different approach. At first I though it was an EDID issue. I tried putting the EDID into the DSDT, but it didn't work. There were many possible reasons why this didn't work. So I tried with a vanilla DSDT and had no trouble getting to a desktop, but without graphics acceleration. Tried with graphics enabler and it worked great, it also listed the card as a Quadro NVS 140M 256 MB, without having to enter the specific information into the DSDT. As there were a few other issues without the other DSDT modifications, I chose to use the modified DSDT from here and restore the video section back to the original with "graphicsenabler=yes" in the org.chameleon.boot.plist. Everything works great and the system profiler has the actual video card information listed per the injection of chameleon. I attached my modified DSDT, just remember to use graphics enabler.