Comment 226 for bug 568611

I have uploaded a revised Natty kernel to the PPA, which should fix the regression some users have reported since the last update (this revision re-instates the enabling of acpi_backlight=vendor parameter by default). The new 'kamal2' Natty kernel (linux - 2.6.38-11.48+kamal2~mjgbacklight5) is queued to build and should become available within the next several hours. Thanks Joshua, Joe, and Lawrence for reporting and helping to diagnose the problem.

    https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight

(Its unclear whether Oneiric also needs "acpi_backlight=vendor"; I'll apply the same fix there if any Oneiric user of the backlight PPA advises me that booting with that kernel parameter fixes their system).