It's been a while since I did it, but I *think* you have to re-enable it from the TV itself. I think disabling it in iTunes disables it on the unit.I clicked on the menu bar down the left side of the iTunes Screen.
The one that lists:
I used to have an AppleTV before I disabled syncing.
Sorry... I know there are contextual items. I didn't associate the left navigation pane in iTunes with the term "menu." You cannot right click on menu items (the ones in the menu bar, what I associate with the term menu), in OS X. You can, occasionally, in Windows.There are right-click menu items in OS X.
I believe the answer to all this confusion actually lies in the fact that the appletv disappears when your itunes library is not selected as the source on the tv. This confused me mightily also.I right clicked on the iTunes AppleTV menu item and selected "Turn off Syncing". The menu item disappeared. How do I restore it so I can re-enable syncing?