Fixing "locale.Error: unsupported locale setting"

The system's locale setting somehow broken, fixed it with change to LC_ALL.
Original solution found here: http://plog.tcc.edu.tw/post/38/1560
Keep here just in case.

[root@test-linux lte]# system-config-network
Traceback (most recent call last):
File "/usr/sbin/system-config-network-gui", line 42, in ?
locale.setlocale(locale.LC_ALL, "")
File "/usr/lib/python2.4/locale.py", line 381, in setlocale
return _setlocale(category, locale)
locale.Error: unsupported locale setting

[root@test-linux xxx]# locale
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
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=

[root@test-linux xxx]# export LC_ALL=C
[root@test-linux xxx]# locale
LANG=en_US.UTF-8
LC_CTYPE="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_COLLATE="C"
LC_MONETARY="C"
LC_MESSAGES="C"
LC_PAPER="C"
LC_NAME="C"
LC_ADDRESS="C"
LC_TELEPHONE="C"
LC_MEASUREMENT="C"
LC_IDENTIFICATION="C"
LC_ALL=C