While I booted up I continually hit Fn+Up/Down until the point when they stopped working. Noting the messages on screen at the time I then booted into recovery mode and manually started S10acpid and bingo the keys stopped working.
While I booted up I continually hit Fn+Up/Down until the point when they stopped working. Noting the messages on screen at the time I then booted into recovery mode and manually started S10acpid and bingo the keys stopped working.