Normally, when you see a file connecting for ages & then it needs more sources, it's a fake file issue. There are fake files throughout the network which will never download & here's some info about them.
Fake files showing up in search results
Do a test...search for an old song (new releases tend to show up as fakes more often) using the All Types search. Look for artist or album rather than song title. Choose a file with 10 hosts or less, or a file with a modem source. Can you download anything?
Some people seem to see this connecting/need more sources crap with every file & I don't know why

Are the LW versions the same on all computers (ie can some comps download but one not, using the same version of LW)?
Try deleting LW's preferences folder when LW's properly closed. See points 2 & 3 below. If you've used LW versions older than 4.9.34 on the comp, you could have a folder in both locations. If not, just check point 3's location.
Fixes for LimeWire
This will kill all of your settings within options, you'll have to go back thru & reset things afterwards.