Album Artwork Scroll Bar Doesn't Work: iTunes 12.1.0.50

I just updated to iTunes 12.1.0.50 for Mac, and the Album Artwork scroll bar no longer works. It scrolls, and the "Album Artwork" and "Other Artwork" headers move," but the artwork itself doesn't move. Effectively, artwork out-of-sight is lost to the user.

I hope you get this fixed soon - I store a lot of artwork in my MP3 files, and I depend on this interface to manage it!

In the example below, there's a fourth album cover in the file; I've scrolled all the way to the right, and it is not visible.