I'm sure that the translation site has always been "standardized" at the correct encoding. See my post in the language forum in the Using Moodle course about this - http://moodle.org/mod/forum/discuss.php?d=13514
I have upgraded this site to the latest stable version - 1.4.1 - and this phenomenon is no longer occurring. "View source" now works perfectly in IE, and shows the correct euc-kr encoding. I think saving a webpage to the computer hard disk is misleading regarding the webpage's real encoding when on the web. Firefox always showed the encoding as "euc-kr" both in the old version and since the site was upgraded. Before the upgrade there seems to have been something strange happening with IE in a place other than the language files.
However, there is no doubt that the encoding was and is correct!
Have you done any translating there recently? Any assistance is always appreciated!