Doesn't recognize S, M keys upon mount error

[Joke de Buhr]

Binary package hint: plymouth

Mountall reported an mount error. Plymouth displayed the partition couldn't be mounted and presented some interactive options.

"An error occurred while mounting. Press S to skip mounting or M for manual recovery."

Neither pressing S nor pressing M worked. The keys were not recognized at all. Other keys like ESC were recognized and tty switching was possible. After switching back to the plymouth screen pressing S or M didn't have any effect.

I wasn't able to get to any prompt and had to do a hard reboot.

Description: Ubuntu 10.04 LTS
Release: 10.04

plymouth:
  Installed: 0.8.2-2ubuntu1
  Candidate: 0.8.2-2ubuntu1
  Version table:
 *** 0.8.2-2ubuntu1 0
        500 ftp://mirror.netcologne.de/ubuntu/ lucid/main Packages
        500 ftp://ftp.uni-kl.de/pub/linux/ubuntu/ lucid/main Packages
        500 http://ubuntu.mirror.tudos.de/ubuntu/ lucid/main Packages
        100 /var/lib/dpkg/status

[Steve Langasek (vorlon)]

Thank you for taking the time to report this issue and help to improve Ubuntu.

What version of the mountall package do you have installed?

[Joke de Buhr (joke)]

mountall:
  Installed: 2.14
  Candidate: 2.14
  Version table:
 *** 2.14 0
        500 ftp://mirror.netcologne.de/ubuntu/ lucid/main Packages
        500 ftp://ftp.uni-kl.de/pub/linux/ubuntu/ lucid/main Packages
        500 http://ubuntu.mirror.tudos.de/ubuntu/ lucid/main Packages
        100 /var/lib/dpkg/status

[ariel cornejo (arielco)]

Bug persists in 14.10. I had to put the missing drive back to be able to boot.

A few observations:
* pressing Control-Alt-F(1-5) results in an unresponsive black screen with just the five dots being repainted.
* pressing Control-Alt-F7 to go back shows the same as above, except every key pressed while trying to skip to that VT is visible and further keystrokes are also echoed.