After downloading a number of movies via iTunes, watching a few of them, with 3 minutes to go until the end of "Bambi" the video just stopped. Returning to the chapter selection we selected the last chapter. The screen went blank, just pure black. Hitting the home button got us out of it, but afterwards we can:
1. No longer run the default video viewer
2. No longer view the movies purchased on iTunes
The "Bambi" movie was a rental, so it's possible that the 24 hour window may clear the cache of whatever the default video app is trying to show, but we're not at the 24 hour window yet.
In the meantime, we followed the suggestions here, including a synch to the main laptop and, unfortunately, we're still in a black screen/no-functionality mode on the default video app.