It’s possible that if those were running, mt-daapd refused to start the rendezvous service. The version of apple’s mdns responder that’s bundled with mt-daapd (58.8) tries to open the multicast socket in a manner that requires exclusive access.
Also, 0.2.1.1 has a known issue on amd64, if that’s what you are running.
The howl solution is the “right” solution anyway… In fact, I think the next version isn’t going to include mdns stuff anyway, but require howl. (or a standalone mdns).
An app that has a built-in mdns responder is just stupid. It doesn’t encourage the adoption of mDNS because all the built-in responders step on each other’s toes, and nothing works the way that rendezvous is supposed to.
In a perfect world, all the distros would ship with Howl anyway.