Thing #7

This is something unrelated to libraries or 23 things, but I am curious about it all the same, and it is technology related. Everytime I allow an update for QuickTime and iTunes to happen, it messes up my ENTIRE library by adding 5 or 6 copies of each song to it and then I have to spend hours deleting all the extra songs back out. I have a very old version of both now, and don't know why it has to do that. Are there really 8 copies of "pour some sugar on me", a leftover from my ex's bad (or good to some) music collection floating around on my hard drive? If Apple software and iTunes is so technologically advanced, why can it not sense that there are too many of each song and eliminate them for me?