I use finnish keyboard all the time. I guess I have just gotten used to it long time ago as changing to US keyboard makes too much hassle when I do something else.
Sure, it's annoying that special characters are in different places, but what can you do...? The only real solution would be coding all keyboard handling like this: "okay, the user pressed shift-seven so the user means forward-slash character, now the action for the forward-slash character in this case is ... "
Not very feasible, plus this extra layer would make a serious hit to gui snappiness