i915kms and Zenbook lcd brightness

[Luke]

I downed the current today and built GENERIC kernel hoping to get my
Asus Zenbook UX31A to work with Xorg (kms) as I see the recent i915kms
work was submitted last week (many thanks to the developers hard work).
However, when X starts it is VERY dim (brightness level 0?) even though
I have loaded the "acpi_asus", "acpi_asus_wmi" and sysctl reports
brightness at "100".
About a month ago I had downed the development branch of this work
(before it was submitted to head) and compiled it and had success using
the above mentioned modules I believe. But it no longer works for me.
Has anyone else noticed this? Have I forgotten a crucial step or is
there a regression in the code or something else at foot here?
Any insight where to look next would be appreciated.
Thanks for your time.