Special Characters - "Nodeadkeys"

If you're using a german keyboard you're maybe having problems with the characters é à ã etc. showing as 'e `a ~a. (If you're having the same problem with another language setting maybe the solution will work, too, but I give no warranty).

The only thing you need to do is

sudo kwrite etc/X11/xorg.conf

(of course using Ubuntu you should use gedit instead of kwrite) - look for the Section:

Section "InputDevice"
Identifier "Generic Keyboard"
Driver "kbd"
Option "CoreKeyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "pc105"
Option "XkbLayout" "de"
Option "XkbVariant" "nodeadkeys"

And then DELETE the line nodeadkeys (do NOT leave an empty line).
Restart your computer - and you're done.