Some time last year after some automatic AppleTV update the thumbnails in my iTunes shared movies library end up not fitting on the screen.
As in the number is say 15. The top 12, three rows of 4 each you can see the thumbnail with the title underneath.
However, the bottom row of three are cut off of the bottom 25% of the thumbnail. You can't see the movie names.
I have looked at all the Apple TV settings as well as the TV settings. I never made any changes to the TV, so I have to assume that something that I can't find access to in the AppleTV is causing this.
An even thought the sharing computer can only run 10.7.5 and the iTunes related to that OS version I never had this problem before some change mid to late last year.