Great that you are going to work on that again. First time I tried, searching the net for drivers and stuff, i got stuck with an hibernation that didn’t work properly and the brightness issue.
Now a I have tried a second time, with Sony OS Migration Drivers, and a had the brightness issue and the S1 na S2 key are not working.
I have a feeling that the brighness issue is only going to be solved if a über geek start messing with the sony/nvidia driver by himself. In fact, I dont even know if it is doable.
I am waiting on you diagnosis.