If you're connection's fine, try this for your problem of no search results.
Problems with the search

If that doesn't help then delete 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...you could have a folder in either/both locations).
Fixes for LimeWire
This will kill all of your settings within LW's options, you'll have to go back through & reset things afterwards