Try d/loading a file from here:
http://www.magnetmix.com/audio2.shtml. Try the first one. It'll d/load in LW. Give it a couple minutes to start. If it doesn't, right click it and have it find more sources. It should start d/loading with good speed.
If it works, then those other files were probably fake and you may just need some pointers on finding good files. If it doesn't work check with your isp to see if they traffic shape p2p programs.
See:
How to find music Fake files showing up in search results (Connecting for ages with many hosts & then Need More Sources when trying to download a file.).