There is a longstanding bug in Musicbrainz that makes it difficult to find songs that contain a number of common stop words such as the,is,that,a . This is because these stop words have been removed from the search index so do not count towards a match. Album such as 'is this it?' by the Strokes have a real problem because it ONLY contains stop words.
I suggested a fix some time ago which didnt get acted on. Ive now implemented the fix successfully on a pure Java development server results at http://www.jthink.net/jaikoz/scratch/isthatitsearch.jpg. I need to reimplement in the existing code base, then hopefully this will prove the fix and get it rolled out.