No, definitely not. It should sound like the MP3 only without the staticy part between the intro and the main theme and generally a bit higher quality all around. Do make sure the 16-bit samples are behaving though, those can add scratch if they're wrong-endian.
Aargh. Second dumb mistake in one evening. The compiler hadn't picked up all the changed files.
Noli umquam docere porcum cantare; perdes tempus et irritabis porcum.