2.99.4.20041128 and Vietnamese Unicode problem

Hi,
Just compiled successfully tetex-2.99.4.20041128. I try a test with
vietnamese unicode input (texmf-dist/doc/generic/vntex/vntest2.tex)
and I have error:

...
(/work/apps/tetex/share/texmf-dist/tex/latex/tools/multicol.sty)
(/work/apps/tetex/share/texmf-dist/tex/latex/base/inputenc.sty
(/work/apps/tetex/share/texmf-dist/tex/latex/base/utf8.def
(/work/apps/tetex/share/texmf-dist/tex/latex/base/t1enc.dfu)
(/work/apps/tetex/share/texmf-dist/tex/latex/base/ot1enc.dfu)
(/work/apps/tetex/share/texmf-dist/tex/latex/base/omsenc.dfu)))
(/work/apps/tetex/share/texmf-dist/tex/generic/babel/babel.sty
(/work/apps/tetex/share/texmf-dist/tex/latex/vietnam/vietnam.ldf
(/work/apps/tetex/share/texmf-dist/tex/generic/babel/babel.def)
Loading definitions for the Vietnamese font encoding
(/work/apps/tetex/share/texmf-dist/tex/latex/vietnam/t5enc.def)
(/work/apps/tetex/share/texmf-dist/tex/latex/vietnam/vncaps.tex))
(/work/apps/tetex/share/texmf-dist/tex/generic/babel/english.ldf))
(./vntest2.aux (/work/apps/tetex/share/texmf-dist/tex/latex/vietnam/t5cmr.fd))

! Package inputenc Error: Unicode char \u8:ạ not set up for use with LaTeX.

See the inputenc package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              
                                                  
l.12 áạ
          à ảãăắặằẳẵâấậầẩẫÄ'éẹèẻẽêếệá»...

?

With the same file, I could compile without problem under tetex-2.0.x
(shipped with Fedora Core 3) + vnTeX (current release at
vntex.sf.net).

I try to install latex-unicode package from
http://www.unruh.de/DniQ/latex/unicode/ (Build date: 2004-17-10 21:38)
and changed:

\usepackage[utf8]{inputenc}

to

\usepackage[utf8x]{inputenc}

and now the compilation passes OK :)

I don't know where is the problem ? tetex-beta (unicode support) or vntex ?

Thank you,

Quy NGUYEN-DAI
-- 
http://vnoss.org