I also find the problem,
The mt-daapd 2.4.0 works fine with iTunes of Leopard OS.
But mt-daapd will have some problem with Front row of Leopard OS;
1. front row can find the mt-daapd server in the sources if only 1 mt-daapd server in the local network,
2. front row can only find one mt-daapd server if more than 1 mt-daapd server in the local network, and some times, the found mt-daapd server will change different time,
3. front row works fine with the iTunes ‘s library shares.
I think the problem may be caused by the mdns of front row in leopard have some special difference with mt-daapds.
-minigabriel