please tell what you have installed from Control Panel .. Reginal/Language Settings.
Far Eastern Langugages?
Complex scripts?
Or none of them?
I think the latter, but please confirm. We have seen those squares at several occasions in the development process, but they should not occur of course (not with only the basic languages installed either of course). They do not either on any of our systems. I do not think English vs. German OS makes any difference.