Try checking them with Bitzi Web Lookup. It'll help you sort out the good ones. While on the Bitzi site, search for the file there and use the magnet link to start the d/load in limewire. Then search for it again in LW to help find some sources for the file.
Also preview the file when it gets to 10-15% to check that it's what the title says and not mislabeled porn.

The files you've been trying to d/load are probably fake. See: Fake files showing up in search results

Try the suggestions in this thread: Problems with the search

Also see: How to find music(and videos)

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