When i see posts complaining about zero search results it's often due to their isp provider filtering their LW. I hope that isn't happening to you.

You can try deleting your LW Preferences folder whilst LW is closed; instructions here: Fixes for Limewire & see if that helps. If it worked ok yesterday but has only now been behaving oddly then it might be a corruption in the LW preferences.

Oh by the way, 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); config instructions: Firewall configuration instructions