Ok, now it works ! Thanks.
Actually it was a configuration problem.
I’ve downloaded the latest software sources archive and extracted the template for mt-daapd.conf file.
It has some differences with the one installed by ipkg from mt-daapd repository. The section [scanning] has been added with the tags “process_playlists” and “process_m3u”.
So I’ve merge the 2 versions of mt-daapd.conf because the newest one is not suitable for NSLU2.
It is supposed to default to the right settings if they aren’t ther.e Clearly they don’t. :/
I’ll explicitly set them in the slug configs.