Apologies if this has already been covered here, but I couldn't find it.
I've found that some of my albums aren't displaying album art on the iPod (60G iPod photo), while they do display art in iTunes (4.9 Win XP). Previously I've fixed this by switching off 'Display album artwork on your iPod', then updating the iPod (all the artwork is then deleted from the iPod). I've then switched 'Display album art...' back on and updated the iPod again (and waited a fair time while it optimizes and transfers the artwork).
This procedure no longer works for me, stopping during the 'optimizing' process with an 'unknown error -50'. And now, of course, I've no album art at all displaying on the iPod.
Anyone any ideas?