Files that sit connecting for ages, then get stuck needing sources forever are usually fake. Look up files with Bitzi before download, see if any other users have rated the file (music doesn't get rated as often as movies).
If a file has heaps of sources but no Bitzi rating, chances are it's a fake. There's a link to Bitzi info in these threads, plus info & tips.

Fake files showing up in search results
How to find music (has tips for video as well)

If this is happening with absolutely every file that you try to download ( do a test...try to download an old song with 10 sources or less), 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