DocLotus,
Unfortunately, we can't reproduce the problem. As Matt mentioned before, we install every build of MC 9 on our computers before we release it on the Interact.
Do you use Update Library tool in Media Center?
If you want more security for your image files, store them in the same folder as music files.
During import, Media Jukebox will find the cover art file and associate it with music file. The other benefit of placing cover art file in the same folder with music is that Media Jukebox stores relative path to the image instead of full path; thus, if you move your music folders, you will not loose image association.
Regards,
Nikolay Sokratov