Blender uses pixmap to display international letters.
As a result, these characters are not so clear.
If we use bitmap instead pixmap, distinct characters are showed as it is in default English version.

pixmap http://bbs.blendercn.org/files/o_189.gif
bitmap http://bbs.blendercn.org/files/pixel_146.gif

For a better view, I replaced button "Use textured fonts" with a menu:
http://bbs.blendercn.org/files/fontmenu_130.gif