There's no simple answer for getting around the fake files on the network. With experience and the proper setup you can avoid most of them.
Try the tips in the links birdy left. Also try the suggestions in this thread for blocking bad ip's:
Problems with the search
Use
Bitzi Web Lookup before downloading. 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.