Thank you for taking the time to report this bug and help to improve Ubunt.
acpi-support is not involved in the handling of these hotkeys. This is a bug either in udev on the input side, or the X server or related packages on the output side. Reassigning to udev; please see /usr/share/doc/udev/README.keymap.txt.gz and follow the instructions described there under "Fixing broken keys" to confirm whether this is a udev bug.
Thank you for taking the time to report this bug and help to improve Ubunt.
acpi-support is not involved in the handling of these hotkeys. This is a bug either in udev on the input side, or the X server or related packages on the output side. Reassigning to udev; please see /usr/share/ doc/udev/ README. keymap. txt.gz and follow the instructions described there under "Fixing broken keys" to confirm whether this is a udev bug.