emacs XIM input method and locale issues

[Shaowei Wang (wsw)]

Hi all
  I want to use xim program(scim) with emacs and I have some issues here.

My scim works find with gtk programs and other X programs(rxvt-unicode) but emacs. I found the locale is the
key point. 

my locale is:
address@hidden ~]$ locale
LANG=en_US.UTF-8
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=


I start emacs like:
LC_ALL=en_US.utf8 emacs -Q  # The scim do *NOT* work.

LC_ALL=zh_CN.utf8 emacs -Q # OK, the scim works fine.

and I grep the emacs source tree, found nothing but:

src/emacs.c  has some functions to set LC_ALL.
=======================

I did lots of google searchs. Some guy said it is the Xorg problem and others said it's the font (may be font path) problem.
But how do we explane that other X program works fine with scim?