This solution worked for me i had the same problem ,limewire couldnot connect.
Download this file gnutella.net.net

and copy it to cocuments and settings-user name-Application data-Limewire!
Delete original file gnutella.net!
Restart Limewire!
Wait a minute so limewire connects to net! It worked for me!

p.m:if limewire still cannot connect try to rename downloaded gnutella.net.net to gnutella.net