Accented characters in author entry

[ntmlod]

At first every accented character was not handle well by bibtexparser.py owing to the use of the original LaTeX syntax with escaped codes i.e. for example \'{e}. So I have modified our original BibTeX file by putting everything inside braces.
It solved almost all typos but I still have some for the author entry. Instead of the good characters I find the Unicode codes è, é and ú respectively for é, è and ' characters.
Give a try to modify default_charset to iso-8859-1 (latin1) or iso-8859-15 (latin9) but no success.