27"iMac11,1/2,8GHz/12GB/i715"MBP3,1/2,4GHz/4GBMini3,1/2.26GHz/2GB, Mac OS X (10.6.4), TC 'sim-d' 500 GBAEBSn2x AX (b/g)ATV 40 GBTouch 2G iOS 4iPad wifi 16 GB
I have experienced exactly the same frustration when setting up my wifes iPad and iTunes.
Even if I copy the files from the shared library to the home library I still can't get the album art work!?
I was not experiencing this until a few updates ago (I think it was 4.3?). Anyway, yes, it's frustrating to try to find a movie on my iPad when a very large portion of the cover art spontaneously mis-align's with the movie it's attached to.
I've searched a lot, and the best piece of advice I found was to exit iTunes, find the iTunes Library index file and delete it. It's located (for Windows users) under c:\users\(your user name)\My Music\iTunes. iTunes Library.itl.
However, this is not the best way I've found. This wipes out your entire library index (both music and movie) which you'll have to recreate.
I did find however, that if you delete all the movies out of iTunes (opting to keep the files of course), exit iTunes, re-open iTunes and re-import from your Movies folder, it does the same thing and seems to reset the box art that goes with the movies. This way I don't have to recreate my music library, or set up Home Sharing again.
I'm finding I have to do this after ripping and importing every 2 to 5 of my movies. My goal is to make them all available to me through iTunes to port to iPad, iPhone and AppleTV. Makes it ever so easy to watch movies for the entire family. Currently at 292 movies and I'm only in the H's.iTunes, Windows 7