I think the search results will also return once-known locations, which doesn't mean the host is currently active. I've had searches come in for files I deleted months ago, which means that somewhere some list thinks my IP will deliver a file I don't have.

I find the cmd-click "repeat search" works well to build up a list of locations (the tooltip lists the numbers of alternates). Once the list is long enough the file can go all night before it runs out of sources to try.

Since you usually run as an Ultrapeer, I'm guessing you already know to force IP in the LW prefs, forward port 6346 in the router and open the Gnutella port in the sharing->firewall tab of your System Preferences.

cheers