Comment 133 for bug 333386

Hi Pablo, sorry for responding that late. The boot option (acpi_video_strict_detect=0) is only useful in Jaunty. Karmic is less restrictive by default and from the dmesg I see that the acpi video driver detects a gfx device. So in all this looks like a different problem and it should get into a new bug report (beside this one being so big one can hardy find information).
So can you please open a new bug by calling "ubuntu-bug linux" on the command line. This will gather basic information and opens the bug. Give it a description like "Acer <your laptop model>: Cannot change brightness (at all | with hotkeys)".
Then attach the output of

- "sudo acpidump -o acpidump.txt"
- "grep -r . /proc/acpi/video >acpi-video.txt"

And finally assign me to that bug. You can also try to use "acpi_backlight=vendor" on the grub commandline and if that changes anything, please note that in the new bug as well.