On my Vostro 1000 notebook the following messages spam my dmesg:

[18678.728936] atkbd.c: Unknown key released (translated set 2, code 0x8d on isa0060/serio0).
[18678.728941] atkbd.c: Use 'setkeycodes e00d <keycode>' to make it known.
[18679.831109] atkbd.c: Unknown key pressed (translated set 2, code 0x8d on isa0060/serio0).
[18679.831119] atkbd.c: Use 'setkeycodes e00d <keycode>' to make it known.
[18679.841607] atkbd.c: Unknown key released (translated set 2, code 0x8d on isa0060/serio0).
[18679.841615] atkbd.c: Use 'setkeycodes e00d <keycode>' to make it known.
[18680.901733] atkbd.c: Unknown key pressed (translated set 2, code 0x8d on isa0060/serio0).
[18680.901744] atkbd.c: Use 'setkeycodes e00d <keycode>' to make it known.
[18680.911536] atkbd.c: Unknown key released (translated set 2, code 0x8d on isa0060/serio0).
[18680.911546] atkbd.c: Use 'setkeycodes e00d <keycode>' to make it known.

It's most probably not from an actual key because it appears in regular intervals. First what is it? It could be my battery since it's nearly dead, as in loadable to 11 % of the initial capacity, but I have no evidence for that.

• What is this / how can I find out where this comes from?
• How can I get rid of it? Is there a 'dud' keycode?

When I assign a keycode with sudo setkeycode e00d $(random keycode) the key does actually get pressed. That makes it impossible to enter sudo password for example. So any 'real' keycode is not an option.

It hasn't been like that half a year ago. Even better than the dud keycode would be a real fix. It happens from 10.04 to 12.04 (before that I don't know).

I did read zcat /usr/share/doc/udev/README.keymap.txt.gz |less as suggested in the Ubuntu Wiki. /lib/udev/findkeyboards && sudo /lib/udev/keymap -i input/event5 produces what appears to be newlines in rapid succession.

sudo udevadm monitor doesn't show the event.