Windows – Adaptive Brightness service with MacBook Pro with Windows 7 x64 RTM

I just installed Windows 7 enterprise x64 RTM on a MacBook Pro unibody using Boot Camp 3.0 from Snow Leopard. Everything installs very smoothly like HP/Copmpaq SmartStart. I noticed, however, that the Adaptive Brightness service stops immediately.

If I start it manually it just stops again. It writes a started and stopped message to the event log but there are no errors.

There is obviously an ambient light sensor as it works in OS X. Does anyone know if it is possible to get Adaptive Brightness service working in Win7?

EDIT:
Maybe I'm just missing something obvious because the keyboard autodim works perfectly. If it is bright the keyboard backlight turns off. If I cover the ambient light sensor (next to the camera in the lid), the keyboard light turns on.

EDIT AGAIN:
I updated the NVidia drivers to 186.81 which I downoaded from NVidia. Had to use a hacked INF to get them to install but it radically improves the performance. However there is not help with the Adaptive Brigtness service.

I found in the NVidia documentation for 186.81 "Note: The Mobile page is not available under Windows Vista or Windows 7." It seems like the Vista/Win7 driver doesn't support NVidia's "PowerMizer" technology yet or at least it cannot be configured.

EDIT:
I think the root problem is that there is no driver for the ambient light sensor.
http://www.microsoft.com/whdc/system/pnppwr/powermgmt/BrightnessCtrl.mspx

EDIT (again):
I am just helping a friend set up Boot Camp on a 2011 MacBook Pro 13" Sandy Bridge i7 and the Adaptive Brightness Service is working out of the box with Boot Camp 3.2. Still doesn't work on my older hardware but appears to work on the current generation.