You might be seeing fake files, these will sit connecting for ages & then get stuck needing sources...they won't ever download. Always chack movies with Bitzi before download. Music doesn't get rated on Bitzi as much...search for artist or album name rather than song title. Use the All Types search. Stay away from popular files with huge numbers of sources.
Fake files showing up in search results

If absolutely everything you try to download gives you the connecting/need more sources message (do a test - search for an old song & try to download a file with 10 sources or less), delete your 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).
Fixes for LimeWire
This will kill all of your settings within options, you'll have to go back through later & reset things to the way you like them.