Duplicate Audiobook Artwork Tiles

Serveral of my Audiobooks in iTunes appear duplicated (see picture). I've read the forums and spent HOURS AND HOURS AND HOURS trying everything I can find and think of, to varying degrees of success. I've sorted audiobooks every way possible, made sure there are not duplicate files, made sure that the track info for all the files within each audiobook match, tried with/without "compilation" checked, added track/disc numbers and removed composers.

The only real success I've had has been in either adding release dates (strangely enough) and changing track names. SOMETIMES, if the track name starts with a number, you can just remove the number to fix it (MAKE SURE THEY HAVE TRACK NUMBERS BEFORE DOING THIS). Changing ALL of the track names to the same thing USUALLY does the trick. But I would really like to keep the individual track names of some of my audiobooks. Any other suggestions?