Is your LW's connection to the network ok (a few Verizon customers are having problems connecting lately)?
If you have all green connection bars, try deleting LW's preferences folder when LW's properly closed. See point 3 below (also point 2, if you've used much older versions of LW in the past).
Fixes for LimeWire

Your router has a firewall, if you want to get rid of the brick wall firewall icon, try port forwarding. The instructions are below.
http://www.portforward.com/english/r...W/Limewire.htm

Remember that the port forwarded thru a router, LW's listening port & port in the 'manual port forward' box must all be the same number