Can you post a screenshot of what is terrible and what is correct?

Created attachment 20586 [details]
Page 3 of the document

Normal Chinese fits each character into a box, like on page 1 of the document, etc.

P.S., maybe xpdf gets it right because I have xpdf-chinese-traditional installed.

Is that screenshot the correct or the incorrect rendering?

The image is of bad Chinese. If it were good Chinese, it would look like:
    授權書
（博碩士論文）
...

CairoOutputdev problem then, Splash renders it correctly

some tricky fonts need hinting to render correctly bug cairo backend use FT_LOAD_NO_HINTING to disable it.

one possible solution is use FT_LOAD_NO_AUTOHINT to replace FT_LOAD_NO_HINTING to
enable hinting to render these tricky fonts correctly.

freetype has FT_IS_TRICKY macro to detect such font face but not applicable to CairoFontEngine.cc because some embedded font doesn't carry family_name in font face strucure for FT to detect. It may require to pass the info from GfxFont.cc by gftFont->getName() to populate font face faimily_name that FT can identify it then use the FT_IS_TRICKY macro to decide hinting or not.

Hi,
I'm quite sorry for making you irritated about this issue for a long time.
 
The latest FreeType2 is changed to enable the hinting for the nameless
TrueType fonts embedded in PS/PDF, so I guess the situation may be
improved if you upgrade FreeType2 to the latest revision on GIT
(after 2010-Aug-28, version 2.4.2 is insufficient). For the background
info, please find discussion in poppler mailing list:
http://lists.freedesktop.org/archives/poppler/2010-August/006303.html