Album art won't tag from Amazon

So I was merrily going through my collection adding album art through the Tag Sources > Cover Art > Amazon.com function, then all of a sudden it stopped working. It will connect and find the album art, but when it goes to tag it is successful in "0 of 0 files" (happens if I have 1 or many selected).

This problem is occurring for all albums. If I manually add art from my hard drive, it will save the tag.

Any help illuminating the problem would be appreciated.

Right click on the cover to see what options you have checked.

The only option available is "correct aspect ratio", which is checked.