I have started to encounter this problem after "upgrading" to iTunes 11. It seems to be just movies that I have purchased and so appear in the iTunes list of movies. I have other movies in my <home>/movies folder that seem to be OK but will check this further now that you have also reported a problem.
I have found that just hitting pause/play twice on the Apple remote restores the sync for another 10 minutes or so.
If a fix cannot be found I might have to restore a system backup that had the previous version of iTunes!
[Thank you for starting a new discussion on this topic]
Thanks for your diligence. I'm going to go ahead and mark this resolved because I think the answer was pretty much obvious from the beginning, viz., that Front Row is lost to us now. I was hoping there would be some kind of fix, but that was just wishful thinking.
Maybe if I had taken precautions the same way you did, maybe then I would be able to restore iTunes 10 and would be able to use Front Row a little while longer. But in over 20 years of being a Mac user, I've never felt it necessary to take such precautions before an update/upgrade of Apple software in the event I would be truly dissatisfied with the new version or would actually lose functionality. So even if I had backups, I've never downgraded software before and don't even know how.
The truth is, if it hadn't been iTunes 11 that broke Front Row for me, it would have been something else eventually. And since Snow Leopard is now 2 generations behind and I'm going to have to trade up at some point, I might as well admit defeat and forget about Front Row.
Apple wins this round, but I'll be more prepared next time so I don't get screwed out of a perfectly good application.
Funny how your question didn't come up on my query until after I had submitted my own version of the question. But reading your question, as well as the replies to it, I see that iTunes may be the culprit after all. I did not realize Apple kind of turned their back on Front Row - at least on the Mac. And my iMac is the original Core Duo (first Intel Mac), and 32-bit, so I can see (if not fully grasp) why 64-bit code taking over more of the OS would eventually lead to my Front Row issues.
I'd say, maybe Apple could transfer something like the Videos app in iOS to the Mac, but of course that would mean a System update, which I stalled out on with Snow Leopard v10.6.8