I wrote the first post, and I have an update. Running LimeWire (reluctantly) as root, I can download. I have the save directory set to /usr/share/media (drwxrwxr-x root media) and my users groups are 'rob wheel floppy usrlocal media'. Also, limewire 1.7c is installed in /usr/local/LimeWire (drwxr-xr-x root usrlocal).
Doing 'chmod -R g+rwx /usr/local/LimeWire' doesn't help.
Hopefully someone's got some advice, I'm jammed.