Mac seeing a duplicate of itself on the network...

I have strange problem on my Mac Pro: once in a while (sometimes several weeks apart), it would complain about detecting a conflict with another machine with the same name on the local network, and change its name to Mac Pro (2), then Mac Pro (3), and so on. The subsequent names would be listed and kept in the list of Bonjour computers amongst the shared ressources in the finder.

I ended up disabling all sharing on the Mac Pro which stopped the problem from repeating itself, but old iterations (MacPro (5) and so on) are still listed in the Bonjour shares, and I'd love to use screen sharing again. Other side effect: my registered copy of Speed Download says I used my license on two different computers and shuts down

Problem started after I replaced my old MP 1,1 with a newer MP 5,1 and cloned the system drive, but I did this kind of things in the past and never had any issue. I also run a MacBook under Lion and a MacMini under Mavericks on the same network and have never had such issue either.

Any clue?

 

Ok, I did not identify why the duplication would happen in the first place, but I found a fix for the old computer instances being listed in the shared resources.

It looks like Apple Airport base stations proxy and cache Bonjour registries: all it needed was to restart the base station to flush old entries.