Juste en guise de bloc-note, ce paragraphe du site de fonz :

- By default, the 0.5 funplug is installed to /mnt/HD_a2/ffp, but
compiled with /ffp as prefix. The fun_plug script creates a symbolic
link /ffp -> /mnt/HD_a2/ffp that allows the programs to run. If you
move the funplug (e.g. to run on a USB stick), and adjust the
FFP_PATH variable in the fun_plug script accordingly (don't forget
to add code to mount the USB stick).

 
Bref, pour faire ce que je veux, je vais devoir me résoudre à modifier à la main le script fun_plug ... Ouch ! Encore un chouette jeu du Dimanche.