why don't you try doing a fresh install,
apt-get remove --purge fmms
reboot
apt-get install fmms
it should automatically fetch your network settings, if not enter them manually, use small picture setting and havoc mode.

make sure that you double check your fmms gconf.xml
vim /var/lib/gconf/apps/fmms/\%gconf.xml
use i to edit, and
esc + wq! to save and quit
you may need to install vim if you dont already have it(apt-get install vim)