I have limewire pro 4.12.3. When I search for a song (in this case an oldie but a goodie) I get lots of results. The # field displays up to 294 which I assume is the most popular (?). When I try to download that one (or any others that seem to be the more popular ones) the downloads hang on 'connecting' and then the status seems to change to 'need more sources' and I can't get the download, it doesn't even start downloading. Any idea why? I've tried setting up port forwarding on my router instead of using upnp but that didn't seem to help (provided I did it correctly which I think I did). I use zone alarm as my f/w but even turning it off didn't help. Any help would be much appreciated. I've tried googling it but no real help, I can't help thinking it's something fairly simple.

Could it be something to do with some files being restricted due to copyright? I ask becuase no one owns copright on classical files (Mozart etc.) and I don't have a problem with them. It seems to be the more popular, recent ones. I apologise if this has been answered elsewhere - I have looked briefly but no joy to this specific question, if I'm wrong please point me in the right direction. Thanks.

Sounds like you're trying to download a fake file. They're common now.
Search again, vary your search terms, try the All Types search. Stay right away from files with lots of sources, go for a file with 10 sources or less, or those with a modem source.

For movies, always check a file before download with Bitzi. A file with heaps of sources but no Bitzi rating is often a fake.
How to use Bitzi

For music, try the tips in this thread
How to find music

And for some general info about these fakes
Info about fake files