Well, I think after the inital startup of LW and the loading of the incomplete downloads, the client tries to connect to the initial hosts. If it can't find them it will let you know that it wants to spread the search terms (i.e. the file name and size, etc.) again to see whether other hosts in this part of the LW-horizon have come online offering the file to download (with horizon I mean that of the whole network you will see/connect each time you go online only to a portion and not to all of it). In case it can't find such new hosts it will get into the "Awaiting Source" mode sending frequently a sreach signal to see whether ahost has come online.....
