Hi Mark,
I can't find tools to test mDNS (yet).
Are jou sure it doesn't matter that the Bonjour-service on the FireFly server won't start? I ask this, because I found the Bonjour-service installed and started on all my clients and the mDNSResponder proces is running. The description stated that this service is needed to notice the existence of other services in the network such as ITunes and Safari.
I disabled the firewalls for testing, but nothing happened. Could it be a Router issue (FRITZ!Box Fon WLAN 7170)?
Rien