problem on first utilisation on fedora

[pierre-étienne nataf]

I used to have LilyPond running on Windows for a while and did really
appreciate but when I trie to instal it on fedora core 3 an run test.ly,
I get this message (I already installed ec-mftraced):

GNU LilyPond 2.4.5
Processing `test.ly'
Analyse...
Interprétation en cours de la musique...[1]
Pré-traitement des éléments graphiques...
Calcul des bris de lignes... [2]
Layout output to `test.tex'...
Converting to `test.dvi'...
Converting to `test.ps'...
Error invoking `dvips  -t "a4"   -u+ec-mftrace.map -u+lilypond.map -Ppdf
test >/dev/null 2>&1 '. Return value 256
Conversion à « test.pdf »...Error invoking `ps2pdf  -sPAPERSIZE="a4"
test.ps > /dev/null 2>&1 '. Return value 256

Thank you for help
P.e Nataf