this has been an issue for god knows how long. I manually meta tagged all my itunes content to ensure they all contained the same info. On tv series I removed any actor, director etc info as this tended to cause shows to be listed multiple times and I added the show name to the album name field. Actor names etc seem fine on movies.
It was a painstakingly long process and after I'd finished I was happy to see that it had worked 🙂 2 x apple tv's, 1 x iphone 4, 1 x iphone 4s, 1 x ipod touch 4th gen and 1 x ipad 2 all showed everything fine. All on most recent fw. Then my girlfriend tried her ipad 1 and disaster! everything in movies was fine but on hers the tv shows all had the same problem. She's running 5.11 which is the newest fw she can have and we just cant get it to work.
seems to be an issue relating to 5.11 as on the newer fw's it's all ok. Have added more films and series since and as long as I've kept to the same meta tagging format all the devices seem happy. Did once forget and added a series with some different info and it threw it all off again. Once I'd sorted the tagging again and disconnected from home sharing and reconnected it was again all good. Is a real pain as it never affects the apple tv's but its been around for well over a year afaik and apple doesnt seem to address it. What I did notice on the ipad on 6.0 is that the films now have the film title showing over the artwork. Maybe that was apples way of "resolving" the issue. At least if the artwork is screwed up you still have the correct title showing. Bit weak imo!