Sorry to ask you to do this (don't hate me

) but can you delete your preferences folder again? Also make sure to look for a folder in the old location of C:\Documents and Settings\your username\.limewire
Do a test. Search for an old song (2 years plus) & try to download a file with 4 or 5 sources, or try a single modem source.
If you like, send me a PM & I'll give you a link to download an older version of LW, we'll see if that makes any difference.