Problem Changing Album Art?

I recently upgraded from a 4S to a 5 and am having problems changing album art of songs that have been synced to my phone. Although the initial sync of my music worked correctly, I have since attempted to change the album artwork on iTunes.

Although this looks like it has worked on my computer, when I try to sync my device, the sync completes and the old artwork remains. How can I correct this?

Any help would be appreciated, thank you!