Hi there,
I have the same issue. So basically when I Rip a DVD into the library I am unable to update the artwork. If I purchase a movie or TV show via iTunes, the artwork is there...Its just updating for me that doesnt work. updating other information like title or sorting or Category - these all work fine.
I wanted to ask something - are all of you using a NAS for your itunes library or are some of your experiencing this with your library on the MAC or via USB? I had loads of errors with my Itunes library being on a NAS type device and the only way I fixed all my previous errors was by opening iTunes in 32bit mode - however this is now not possible.
My next test is to see if I use my Windows machine to import the move, change the artwork, then try copy that to the MAC and reimport...Mission but would be good to see if this would work.
Its very annoying and it seems we all have issues but no official acknoledgement from Apple?
J