Hello, I have had this problem on both versions of this player and its doing my nut. I have tagged all of my music using MP3 Tag Tools and WMP automatically picks up and adds the tracks to its library, but after a few minutes it keeps reverting the tags of my music to what they were before I modified them, i.e on certain albums I have changed the genre etc.... its a pain because it then splits the albums into 2... I keep chenging them back and gues what WMP changes them back again. It doesn't happen when just using iTunes. Does WMP use any files to store library info?. Does anybody have any knowledge of this... I found another site where someone had this problem but there were no responses.