[texhax] bibtex changes file charset

[kyanh]

Hi all,

I have a strange problem with bibtex + biblatex on my Linux system. The 
problem is that the charset of xyz.bbl was incorrect after running 
bibtex + biblatex.


$ tex --version
TeX 3.141592 (Web2C 7.5.4)
kpathsea version 3.5.4
...

$ echo $LANG
en_US.UTF-8

$ latex xyz
# no errors

$ bibtex xyz
# no errrors

$ latex xyz
./xyz.bbl:18: Package utf8x Error: Malformed UTF-8 sequence.

$ files -i xyz*
xyz.aux: application/x-empty
xyz.bbl: text/plain; charset=iso-8859-1
xyz.blg: text/plain; charset=us-ascii
xyz.dvi: application/x-dvi
xyz.log: text/x-c++; charset=us-ascii
xyz.tex: text/plain; charset=us-ascii

The charset of xyz.bbl should be UTF-8/us-ascii instead of ISO-5589-1.

Is there anyway to fix this  problem?

Thank you very much for replies.

Regards,


kyanh

--

xyz.tex:

\documentclass{article}
\usepackage{biblatex}
\usepackage[utf8x]{vietnam}
\bibliography{main}
\begin{document}
\cite{KYANH}
\printbibliography
\end{document}

main.bib:
@MASTERSTHESIS{KYANH,
	author = {Kỳ Anh Huỳnh},
	title = {Mặt BLW và Bài toán Bj\"orling},
	year = {2006},
	school = {Huế University},
	country = {Vietnam}
}