Problem with keyboard distribution and diacritics (12.04)

[Carlos A. Carnero Delgado]

Hello,

I have a problem with the keyboard distribution and Kubuntu 12.04. The
physical keyboard on this PC is laid out for Latin America (i.e., it
has the Ñ key) so I did what I have done in the past many times: set
Spanish (latin american) as the proper keyboard distribution.

Everything works except for very annoying exceptions: diacritics. I
break down below the results of simple tests in case someone can see a
pattern evolving:

* in LibreOffice applications diacritics will not work at all:
  neither acute accents (úéí) nor diæresis (üëï).

* in KDE native applications I can compose all characters
  except the diæresis. The physical (dead) key has both the
  acute accent and (shift) the diæresis. When I try to use
  the latter, it will just interpret it as the acute accent
  (as if the shift modifier is not working.)

* in Firefox and Komodo Edit, both GTK-based applications
  IIRC, I can write anything. I just included here for
  completeness sake.

Please note that, while this keyboard has dead keys (the one with the
acute accent and the diæresis being one of them), there is no need to
use the compose key when writing Spanish texts. Besides, in *this*
particular keyboard I have never needed to configure it in the past.

Ubuntu/Gnome 10.04 LTS did not have this minor problem. And I just
booted into the Ubuntu/Unity 12.04 live CD and everything works as
expected.

Is there anything I can check?

TIA,
Carlos.