I think it just means that the search phrase is too long

In my experience with Limewire, I have found it better to be not that specific and getting much better results that way

One thing that I have gotten a lot of rare files with is typing only part of the song name and part of the artist name, different parts of the names will often get different results

I have been able to get several results that didn't show when typing the full name

Also when typing the full names often junk results that only hurt your searches are triggered

Hope this helps