You may have to either reinstall xkb or manually edit xkb; it could be confused.
If reinstallation does not work, here is a good resource for modifying/customizing keyboard layouts:http://archive09.linux.com/feature/113715
Keep in mind that if you do resort to tweaking xkb, you will have to figure out what exact keyboard layout is being used and change the proper file ([whatever menu selection is needed, if any, depending on desktop environment]->preferences->keyboard->layout(tab) can tell you this).
Other than that, I don't know what to say.
They say that a three-year old can use Windows 8. I say that's a bit of a regression. When I was three, I could use DOS.