Letters Å Ä Ö won't work on Mac OS X

Ok, so when I'm typing in the letters Å Ä Ö none of them will come up either in chat, within commands or even naming a world. But I saw a player type those letters, but he was probably on Windows. And I've tried changing the language of the game but that doesn't work at all. Mojang, you gotta fix this!

Kör hårt Jens (Jeb)!