Just make sure that you're not trying to download fake files. Always check video files before download with Bitzi (music isn't rated as often as movies). If a file has heaps of sources but no Bitzi rating then chances are it's a fake.
Fake files showing up in search results

If every single file that you try to download gives you the connecting/need more sources thing, 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.

I have Vista, I have no idea how to locate the preference file through this OS. I tried to search it, and I checked the search for hidden file option, but it didnt find it, either.

Check this out for info about showing hidden files & folders in Vista.
LimeWire Pref Folder in Vista

The folder should be in the same location as shown in the 'fixes for LW' thread that I originally linked to.