It's a Non-Unicode thing setting. Guide is here! Japanese Fonts
I followed it, restarted my computer, reinstalled the game, and it works like a charm!
EDIT: Maybe you can try doing this setting without uninstalling. I lost all my load games...
The link that you posted is broken...could you possibly post up a new one? I'm on Windows 7 Home Edition and I've been having problem setting the language on my computer to Japanese, or really, just installing a Japanese language pack in general.
wohoooo... This is a year late but thanks to this I found the new one. Here! Setting Non-Unicode Programs - Windows 7 I hope this link helps me too. Haven't tried for a game yet.