Keyboard does not work for user with old config

[Michael Schürig <michael.lists@schuerig.de>]

Since a recent update to the current packages in unstable the keyboard does not work anymore in my old user account. For a newly created user everything appears to be working fine.

My KDE config has evolved over the years and is dear to me, so I'd rather not throw it away completely. In order to narrow down the search, I'm looking for suggestions which component (and which config file) might cause all keyboard input to be ignored, blocked, or eaten.

Thanks,
Michael