screen? Sometimes when it syncs, from the main details page on iTunes, it will sync on iTunes but the iPad screen still shows the home screen with icons.
It's a glitch with the iOS software. My iPhone does it sometimes, usually when I get a text or push notification in mid sync. Its nothing to worry about. My only advice is to not mess with it until iTunes says it's done. Otherwise you could cause odd things to happen like missing apps and duplicate media items.