i would never stick to vista just because brightness is not working, this would be like stepping over from a ferrari to a volkswagen just because the left door is not opening.
we just have keep on asking. but what i am figuring out, when i search the net for who is in charge of providing hotkey-functions on a sony-laptop: it looks like sony is the one to ask,
u can read this on the nvidia-website when u are on vista and try to get a driver.
the following message appears:
Sony requires that you download the driver for your GPU from their support site.
You can find more information at: http://www.sony.com.
The GeForce M series and GeForce Go series notebook GPUs use drivers that have been customized by the notebook manufacturers to support hot key functions, power management functions, lid close and suspend/resume behavior. NVIDIA has worked with some notebook manufacturers to provide notebook-specific driver updates, however, most notebook driver updates must come from the notebook manufacturer. Additionally, the desktop GeForce graphics drivers will not install on Geforce M series and Quadro M series notebook GPU's.
it seems to me the best idea to send a request to sony as well till one of both will be willing to provide us with basic functionality or at least tell us clearly who is in charge on this matter.
it is not clear to me and it seems that the linux-team of nvidia does not know (or does not clearify) this either.
in the meantime check out this site: somebody is trying to build a driver: