How are you connected; i.e.: T1 line, DSL, Cable modem, etc.?
Also, are you using a router? -You may have to 're-set' them.
After opening the Limewire application you still have to manually 'connect' from the 'File menu' on top of your screen (upper left).
'Limewire' pretty much configures itself by opening port 6346 .
Sometimes even a simple 'restart' takes care of the problem.