Comment 7 for bug 821586

I now believe this is a problem with oneirics xkb configuration and/or the xserver. It seems there is little that Onboard can do about it at the moment.
I've filed a fresh bug #837456 for Xorg with as much information I could come up with and will mark this one as a duplicate. A dedicated X bug may increase the chances for a fix.

The best workaround I could come up so far is
$ setxkbmap de

but this still has to be run once in every session.