This same problem keeps happening over and over. I sync my iphone with my PC and change the artist names and genres to match what they should be. I do this because I want to be able to shuffle a certain genre or artist in my ipod. Then I unsync my phone and open the ipod on my phone and it tells me it is updating the library. After its done updating, it has gone through and messed up what I did. It takes any song that features more than one artist and makes it its own artist. It changes the genres of a lot of songs. Its really annoying. Is there any way to make it stop doing this?
This used to happen to me because I was making the changes in the music folder, to the files themselves. iTunes will mess that up. But if you use iTunes to make the changes, they'll stick. A small downside to making too many changes is that iTunes cease to associate album artwork with a song or an album. That help?