Since I use Windows and Linux simultaneously (at least since 6 years), the key on a german keyboard on windows to switch on all layers is Ö (right to the L).

in Ubuntu it doesn't work and never has for me.

Is there any reason behind that? After some research it seems as if Blender didn't recognize a lot of special keys (mostly keys between the letter keys and return) for keyboard shortcuts while it easily manages to do so for typing text. They don't work in the game engine as well. I can't imagine this to be a bug since it's been like that forever. Is there a setting I miss?