Make sure your connected for a while before doing searches, it sometimes take a few minutes to build a lot of hosts.
Then if your still not getting results, hightlight one of your Ultrapeers in the connections window and Remove. LW will look for a new Ultrapeer to take its place and you can search all over again on a new set of hosts. To do a re-search on the same file, right-click on the search results tab (the one with the name of the file your looking for) and select 'Repeat Search'
