Comment 36 for bug 204378

I've linked a related Debian bug report, which may provide more info.
I've attached my acpi-support branch, which at least provides a better/cleaner fix for bug 189889, merged from Debian and other fixes. You can either checkout the bzr branch [1], view the changes and/or build the package yourself or test the package from my PPA [2].
Maybe it helps already.

[1] https://code.edge.launchpad.net/~blueyed/acpi-support/cherry-pick
[2] https://edge.launchpad.net/~blueyed/+archive/+index?field.name_filter=acpi-support (0.109~blueyedppa14 or later)