LinuxQuestions.org - diff setup on locale behavior (when using su as login)

Hi, i'm experiencing locale behavior differently when using the exactly same setup, thank you for helping in advance:

Background: have 2 acct, acctA and acctB, acctA uses LC_ALL en_US.UTF-8 setting, and acctB uses LC_ALL zh.TW.Big5 setting. if I wanna display chinese char (big5 code) while I'm in acctA, all I have to do is su acctB, and i can write chinese in app such as OO and such...

Problem: trying to display chinese char (big5 code) at xmms playlist correctly (this can only be done in acctB, and given the font was already changed within xmms under perference), instead of logging in and out, I try to change locale in acctA by issue export LCC_ALL=zh.TW.Big5, before play xmms. here's a interesting msg i get: when i do xmms&

Code:

Gdk-WARNING **: locale not supported by C library

playlist would only display part of chinese char
now... lets try acctB by issue: su acctB (follow by password), then do xmms&

i get:

Code:

The font "-adobe-helvetica-medium-r-*-*-8-*" does not support all the required character sets for the current locale "zh_TW.Big5"

  (Missing character set "BIG5-0")

The font "-default-ming-medium-r-normal-*-*-160-*-*-c-*-big5-0" does not support all the required character sets for the current locale "zh_TW.Big5"

  (Missing character set "ISO8859-1")

yet... i'm able to display chinese char correctly!!! wow... now what just happened? :eek:
i'm very confuse.

it seems like to me locale may not behave the same, if one change locale by doing: export LC_ALL=(lanaguage) and to do export LANG=(language)

compare to locale setting has been pre-coded within shell startup.

so my question is: are there extra steps to do, when changing locale, in order to have it behave the same as locale has been hardcoded during startup shell?

thank you