It sounds to me like you are acting as an ultrapeer. And thus receiving incoming searches from users not necessarily searching your files but simply passing through your LW. The advantage of being an ultrapeer is more connections, the disadvantage is a slight increase in traffic, and slight increase in computer memory use.

This might not necessarily the case that you are a UP, but it may be some of the search terms are linking to id3 tags and may only be partial word links.

Ultrapeers are who you connect through to reach the gnutella network. They also take up some of the search traffic. Their greater connections will also help them in their searches and possibly downloads also. Uploads may be partially affected however.