I can't completely answer your question, but when you do a search you don't connect to every computer on the network. Your searches only go so far. Chances are that your not connecting to anyone that has uploaded your files.

Every time you startup LW you connect to different peers and ultrapeers. So potentially you can find different files than the last time you were connected.

There are millions of people using Gnutella clients and billions of files being shared. So it can be like finding a needle in a haystack.

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