Try clicking to show all results in the boxes to the left of the search results. Otherwise, it might be your junk filter...have you set it to not display junk? If that's the case then it would explain results disappearing, if your LW has recognised the files as junk. You could try changing your filter options to display junk at the bottom of search results...then do another search for the same thing & see what happens.

If that advice sounds wrong for you, try deleting your preferences folder while LW's closed. See points 2 & 3 below. Deleting the folder will kill all of your settings within tools > options, so you'll have to go back & reset things afterwards
Fixes for LimeWire

**Be very careful when downloading programs. They're often infected. Scan all files you've downloaded with your AV before opening!
WARNING: Viruses on the network you should be aware of