i start mine bone-side up - i don't give a dang where that information comes from - the neely's the pitmasters, the japanese parliament - myself, i read it on the BBQFAQ.
anyway, i do it for exactly the reason stated, becasue of the basting effect and the retention of the juices. i baste it a couple of times across the ribs during cooking to prevent the problems that pepe mentioned. somewhere in the cooking process, i flip them over, and i ALWAYS finish and glaze them bone-side down for a nice presentation.