iTunesU sync

I have subscribed to courses on my iPhone 4, within the iTunes U app. I have changed the settings on my iPhone to sync iTunes U. I have tried to sync with iTunes on my MacBook Pro 2009 without success. iTunes thinks I have not subscribed to anything. The courses I have subscribed to do not appear elsewhere in iTunes e.g. in Books or Movies. The iTunes sync settings show that all iTunes U content will sync. Not sure what to do next.