Files that sit connecting for ages & then get stuck needing sources are usually fakes. Have a look at the threads below for advice & tips.
Fake files showing up in search results
How to find music

But...if this is happening with every single file that you try to download, try this: Delete LW's preferences folder when LW's properly closed. See point 3 here & also point 2 if you've used older versions of LW in the past (there could be a folder in either location).
Fixes for LimeWire
This will kill all of your settings within options, you'll have to go back through afterwards & reset things. If you're not sure of your settings, go through LW's tools > options & write them all down, so that you can reset things later.