Try deleting your LW Preferences folder whilst LW is closed; instructions here: Point #2 in Fixes for Limewire (sample at bottom of page.) If this doesn't do the trick, then try step #1 in that link!

Did you configure your firewall so it allows LW full access (advisable not to have 2 active firewalls b/c they can interfere with each other); Firewall configuration instructions (click on link)