If you're sure it's not fake files that you're seeing...
Fake files showing up in search results
...and if it's happening with absolutely every file that you try to download, try this: Delete LW's preferences folder when LW is properly closed. See point 3 below (also point 2 if you've used much older versions of LW in the past). This will kill all of your settings within options, you'll have to go back through & reset things afterwards.
Fixes for LimeWire