iTunes music syncing problem

[TJone]

iTunes is no longer allowing me to transfer only selected music to my iPhone 4. I have the option checked for "selected playlists, artists, albums..." but my entire music library still shows up on my iPhone after syncing. It seems like iTunes does not see that all the music is on the iPhone or there is some other issue going on. I just have put checkmarks next to a few artists but my entire library still shows up after a sync. I am thinking of renaming my Music folder (/var/mobile/Media/iTunes Control/Music), making an empty Music folder and then resyncing to see if that fixes the problem and only transfers the music with checkmarks. Or maybe that will corrupt the file system? Any other solutions? I am trying to avoid restoring. I moved my iTunes library to an external drive a couple of months ago through iTunes but I am not sure if this is related. Thanks a lot..