I can confirm that the bug is present in the latest version of fluidsynth upstream, and I have created a ticket upstream as well. You can follow this bug report here:
http://fluidsynth.resonance.org/trac/ticket/45 -- To UNSUBSCRIBE, email to debian-qa-packages-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
