IT WORKS

all you have to do is (I have FEDORA but it's the same for all distros):

1) open port 49152 in the firewall configuration. In Fedora, italian version:
→ System
→ Administration (maybe, traduced from italian)
→ Security and Firewall
→ Other ports
→ add 49152 - tcp
2) download libupnp (now 1.3.1) and linuxigd, the first downloadable also from repository (so execute "yum install libupnp")
3) compile linuxigd with "make" and follow the INSTALL instructions. few commands to cut&paste!
4) finally, execute the daemon from the installation directory of linuxigd:
./upnpd eth1 eth1

now you server must work. in particular mediatombworks great with both canola e mediastreamer, photos, videos and music.

rhythmbox: still doesn't work