No covers after copying shared iTunes songs
My experience:  there are 2 ways that itunes associates art work with songs:


one is in the "Album Artwork" folder in itunes.  this can be updated from inside itunes in the menus.  these images stay in a folder and get some soft association with the music files.
the other method is added manually with the gui, cutting and pasting.  these get added into the mp3 file.


it seems to me that i've tried to xfer the album artwork folder different ways before, but it doesn't work unless you copy the whole itunes setup.