There is a problem with one of the LimeWire servers (it isn't there at the moment).
You need an address to kick start LimeWire (an entry point for the gnutella network).
Go to the connections tab (you may need to enable it from the 'View' menu item) and enter 208.239.76.100 and click add.
See the thread at
http://www.gnutellaforums.com/showth...threadid=15049
Mark