gnus can not decode some chinese mail?

[wen li]

Hi
yesterday I upgrade my emacs form 23.0.50 (unicode-2) to 23.0.60.1(unicode-2), and now I can not read some chinese content mail,
it's strange because some mail displayed properly but some not, my gnus is v5.11
 (No Gnus V0.7 still not work), my linux box is FC8 X86_64,
and I attach two mail files (I use nnml) and two screen shots, 'mail1' can not be displayed properly, as 'pic1.png' shows, the subject of mail is good,
but content is rubbish.  'mail2' can be displayed as it should be, as 'pic2.png' shows. Note these two mails are all 'gb2312' encoded.
my locales are:
[michael@localhost emacs]$ locale
LANG=zh_CN.UTF-8
LC_CTYPE="zh_CN.UTF-8"
LC_NUMERIC="zh_CN.UTF-8"
LC_TIME="zh_CN.UTF-8"
LC_COLLATE="zh_CN.UTF-8"
LC_MONETARY="zh_CN.UTF-8"
LC_MESSAGES="zh_CN.UTF-8"
LC_PAPER="zh_CN.UTF-8"
LC_NAME="zh_CN.UTF-8"
LC_ADDRESS="zh_CN.UTF-8"
LC_TELEPHONE="zh_CN.UTF-8"
LC_MEASUREMENT="zh_CN.UTF-8"
LC_IDENTIFICATION="zh_CN.UTF-8"
LC_ALL=

and my .emacs file:
......
 '(current-language-environment "UTF-8")
......

thanks very much!

mail1
Description: Binary data

mail2
Description: Binary data

pic1.png
Description: PNG image

pic2.png
Description: PNG image