I take it you've been buying US releases? Yeah, they usually are "best of" soundtracks, which invariably results in good tracks being left off. Japanese soundtracks are almost always complete, though, even down to the little jingles and fanfares and other bits and pieces that most people couldn't care less about. I'd guess about 20% of the Ocarina of Time soundtrack consists of tracks that are under 10 seconds a piece. :P