see discussion in https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/685727?comments=all for similar backlight off problem in 10.10 kernel 2.6.35-24 for Gateway NV79. Issue did NOT occur for Lucid 10.04 kernel 2.6.32.27.
see discussion in https:/ /bugs.launchpad .net/ubuntu/ +source/ xserver- xorg-video- intel/+ bug/685727? comments= all for similar backlight off problem in 10.10 kernel 2.6.35-24 for Gateway NV79. Issue did NOT occur for Lucid 10.04 kernel 2.6.32.27.