Should work great on 10.3.4 (not 10.0.4???) . . . but Apple's java for classic is really old and buggy, and looks like many developers have given up on supporting it.

Anyway, most of us are pretty rusty on classic, but there are some tricks:

Play with the memory allocations (get info)--LW needs 60,000KB.

Check that you have the right java (MRJ 2.2.5) http://docs.info.apple.com/article.html?artnum=75097

Download only a few files at a time, and keep the incomplete folder cleaned out between sessions.

Repeat search to find many sources for files, because if a host is busy or goes offline, you can wait weeks for that one host to come back online.

Read the other posts about OS 9. . . especially those by bootylicious

Since there aren't any other gnutella filesharing apps for OS9, Google for Carracho or maybe you can find an old Hotline client.