Multi Language problems

[GrendelKhan{TSU]

Sorry if this it the wrong forum

PROBLEM:
I have developed (mostly) a Korean language pack.
It uses the correct language codes and character sets ("kor" and "euc-kr"),
but when I post in Korean certain character combos result in a "?"

E.G. (Don't know if you can see this but):
The character: "화" (g-h-k on Eng keyboard) becomes "?" when posting and anywhere in the post (content).

so 돗트 배경화면 샘플2 becomes 돗트 배경?면 샘플2
(see attachment)

Any ideas what is going on?

when I go into EDIT the character back, it works (saves properly), but obviously this is unacceptable as I can't do that for every instance of members posts. IE: this basically makes vb unusable in Korean. (as "화" is a very common character).