Okay. Look like the service files are properly generated. What happens if you run following commands:
service avahi-daemon stop
avahi-daemon --debug
That's what I get:
root@nas:~ # service avahi-daemon stop
Stopping avahi-daemon.
root@nas:~ # avahi-daemon --debug
Found user 'avahi' (UID 200) and group 'avahi' (GID 200).
Successfully dropped root privileges.
avahi-daemon 0.7 starting up.
Loading service file /usr/local/etc/avahi/services/ADISK.service.
Loading service file /usr/local/etc/avahi/services/AFPOVERTCP.service.
Loading service file /usr/local/etc/avahi/services/DEV_INFO.service.
Loading service file /usr/local/etc/avahi/services/HTTP.service.
Loading service file /usr/local/etc/avahi/services/HTTPS.service.
Loading service file /usr/local/etc/avahi/services/MIDDLEWARE.service.
Loading service file /usr/local/etc/avahi/services/MIDDLEWARE_SSL.service.
Loading service file /usr/local/etc/avahi/services/SFTP_SSH.service.
Loading service file /usr/local/etc/avahi/services/SMB.service.
Loading service file /usr/local/etc/avahi/services/SSH.service.
Joining mDNS multicast group on interface ix0.IPv4 with address 192.168.168.2.
New relevant interface ix0.IPv4 for mDNS.
Network interface enumeration completed.
Registering new address record for 192.168.168.2 on ix0.IPv4.
Server startup complete. Host name is nas.local. Local service cookie is 1338253256.
Service "nas" (/usr/local/etc/avahi/services/SSH.service) successfully established.
Service "nas" (/usr/local/etc/avahi/services/SMB.service) successfully established.
Service "nas" (/usr/local/etc/avahi/services/SFTP_SSH.service) successfully established.
Service "nas" (/usr/local/etc/avahi/services/MIDDLEWARE_SSL.service) successfully established.
Service "nas" (/usr/local/etc/avahi/services/MIDDLEWARE.service) successfully established.
Service "nas" (/usr/local/etc/avahi/services/HTTPS.service) successfully established.
Service "nas" (/usr/local/etc/avahi/services/HTTP.service) successfully established.
Service "nas" (/usr/local/etc/avahi/services/DEV_INFO.service) successfully established.
Service "nas" (/usr/local/etc/avahi/services/AFPOVERTCP.service) successfully established.
Service "nas" (/usr/local/etc/avahi/services/ADISK.service) successfully established.