Comment 1 for bug 399587

What is the /etc/acpi/events/tosh-video_brightnessdown shown in this acpid output? This is not part of the acpi-support package in jaunty, and the /etc/acpi/video_brightnessdown.sh it points at is obsolete and being phased out.

The correct fix for this bug is for the toshiba kernel module to generate a key event using the kernel input layer. Can you follow https://wiki.ubuntu.com/Hotkeys/Troubleshooting to verify whether the kernel is outputting a key event, and if not, can you check whether this is fixed in the 2.6.31 kernel in karmic?