about gtk_set_locale

[Takdir CHOWDHURY <takdir mcb netwk ntt-at co jp>]

Hello
I am facing a problem with gtk_set_locale() .
I want my gtk application to show Japanese character. 
And for that I have included gtk_set_locale() in my main routine and changed
 my LANG to ja. But when I execute my program it crashes with core.
The error looks like the following. It was taken from dbx.

current function is gdk_set_locale:
  if (!setlocale(LC_ALL,""))  line 107 in "gdkim.c"

Note that if I set LANG to "C", it works.
Atfirst I thought my libc doesn't support the locale. But I can display Japa
nese with the other GTK+ applications(like gcalender) that come in default w
ith 
gtk+ archive.

Any clues?

----
Takdir