If you manually edit an item name to include those characters, does the game itself display them properly? There isn't much point in fixing the item editor if the game also has a problem. In the disk version of the game there were some problems transferring saves between different language versions, as well as a problem replacing English files in the Thai localization, but I don't know if that was due to changes in the file structure or lack of unicode support, etc.
I may be able to check a manual edit (at least in the disk version) later tonight, or tomorrow...
BTW, anyone still reading the DD forums would be checking both General and Help/Tips/Tricks.
