I have some potentialy interesting observations to make about the cover art issue (size and resolution restrictions)
I don't actually think there are any restrictions. I had a mixed bag of albums that did and didn't seem to display artwork, however I noticed that some of them that did were very large, some up to 3000 x 3000 and close to 5meg in size. I decided to manually re-tag all my music using MP3tag, using the largest covers I could find for most, averaging out at about 1200 x 1200 and around 700kb.
Guess what... They all display fine!
Now this could be something to do with the latest firmware update to 1.32, although I didn't see any mention of it. Or it could be to do with the tagging method, as I used MP3tag for the entire lot.
Bottom line is I have about 80 or 90 albums loaded with not one cover missing.
As a test I would be more than happy to try loading a song anyone is having issues with here and see if it is just a fluke.
One downside I noticed was the scan seemed to take a LOT longer than usual, but having said that I was really pushing it with the sizes to test the limits