For some reason, most of my artwork in iTunes 10 is missing completely. It was there before I updated, and now only 1/4 of the previous artwork is still showing. I tried changing the size of the images, extending the bar out, etc. and it's just not there. But when I switch to other views (Cover Flow, list, artwork only) it is all there. It's even still in the information. But it's not coming up under the Album List.
MacBook, Mac OS X (10.6.4), 2.2 GHz Intel Core 2 Duo, 4GB Ram, 160g