iTunes Movie Artwork Issue For Videos Purchased From iTunes

There appear to be a number of different issues with iTunes and Movie Artwork but my issue seems to be a little different – and I have a workaround for it – so I thought I'd post it here in the hope that it will save someone else some time.

Config: iMac 27" / Latest Mountain Lion / Itunes 11 *in 64 bit mode*

Issue: HD movies purchased and downloaded in iTunes won't let me add artwork. I use 'get info' on the movie in question, select the artwork tab, and then drag a picture across from Google Images. It appears to work fine. I collapse the 'get info' window. To check to see if the artwark was saved, I use the 'get info' command on the same movie. The artwork is not there. It was not saved.

Additional Info:

1. I have no problem adding artwork (using the exact same process) to any movies that I've ripped from DVDs using Handbrake.

2. I discovered that the movies in question that I downloaded wouldn't play when launched from iTunes. The failure message said that playback required Quicktime. I have old and new versions of Quicktime on my Mac. Didn't seem to make sense. I researched the failure to play problem and the workaround for that also fixed my artwork problem.

Workaround:

1. Quit out of iTunes.

2. In the applications folder, find iTunes, right click the app file and select 'get info'.

3. Tick the box that says "open in 32 bit mode". Collapse the 'get info' window.

4. Open iTunes.

5. Launch the movie in question. If you get a failure message, just hit 'cancel'. The movie will open and begin playing, likely with no sound.

6. Quit the movie.

7. Select the movie in question and do 'get info' on it.

8. Select the artwork tab and drag your artwork into the blank window. Collapse the 'get info' window.

9. Repeat steps 5 through 8 for all the movies you've had trouble with.

10. Repeat steps 1 through 4, but this time untick the box that says "open in 32 bit mode".

All your artwork should be ok now, and you should be able to make changes for those files from this point on without using this workaround.

So - my question is, does anyone know why there is an issue with 32-bit vs 64-bit and if there is a way to fix it so this workaround isn't needed?

Cheers.