Because Kazaa & LW are totally different programs that run on totally different networks (remember some of Kazaa shared files were stored on a server.) No gnutella program will allow you to requery or do "forever" searches. See the 1st link called "Requeries" in this post: To continue files downlding (click on link) ie: requerying would slow the network down dramatically! If you want more tips about searching & downlding then follow all the links from the 2nd link on that page.

I tried Kazaa & also tried a similar one. Yes the searches could extend for up to an hour or even much longer. But that causes traffic.