I think your files might have gone to /Volumes/Big Fat Mac 7/<pathtoyourdownloadfolder>

When you ran Limewire with the drive disconnected, it simply created the folder it was looking for by itself. So when you mounted the drive again, it couldn't be mounted at /Volumes/Big Fat Mac 7/ and the System gave it a new name (Big Fat Mac 7 (1)). So Limewire is still using the directory it created itself, while your drive, using a new name, is ignored.

Use the "Go to folder" menu command and copy the files to your external drive in the finder, then remove the folder (to delete it, you might have to use the terminal and sudo or use another way to get root access) and remount your drive. It should have the original name again.