TeX's algorithm for hyphenation gives up when it encounters an
\
accent
command; there are good reasons for this, but it means
that quality typesetting in non-English languages can be difficult.
For TeX macro packages, you can avoiding the effect by using an appropriately encoded font (for example, a Cork-encoded font - see the EC fonts) which contains accented letters as single glyphs. LaTeX users can achieve this end simply by adding the command
\usepackage[T1]{fontenc}to the preamble of their document. Other encodings (notably LY1, once promoted by Y&Y inc) may be used in place of T1. Indeed, most current 8-bit TeX font encodings will 'work' with the relevant sets of hyphenation patterns.
In the future, perhaps, Omega will provide a rather different solution.
This question on the Web: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=hyphenaccents