Do you see a brick wall in front of the blue world icon at the bottom of LW's interface? (see sample attachment below)
When no search results come up at all, it tends to suggest ISP (internet service provider) intervention & filtering/shaping/blocking.
Try an experiment, try downlding a magnet link from here & tell us what happens:
http://www.magnetmix.com/video.shtml
Can you give us a total description of your set up:
1. OS version? (eg: Windows 98)
2. What firewalls you have?
3. How much ram?
4. Hard Disk space available?
5. Connection type? (eg: dialup, broadband, cable, etc.)
6. Modem & router brand name & model numbers?
7. Where are you trying to connect from (home, school, work, etc.)?
8. What version of Limewire (LW) & Java do you have? (Go to LW's menu Help>About LW...) Will show both LW & Java version.
9. Who is your isp provider (Internet Service Provider)?
10. Are you sharing the connection with other computers or p2p sharing programs? If yes, please give details of set up.
11. Is this a your 1st try at LW or is this a new problem with an experienced user.
12. Do this test:
Bug Report instructions & sample image Is the result True/False?
13. Do this simple test for us. Using your browser go here:
http://www3.limewire.com:6346/ The page should say 'Your test worked!'. What happens when you go there?