Image rebuild does not replace album cover files

From what I can tell, when you run the image rebuilder it does not copy the new thumb file to the .album.jpg file. This might not be a problem for most users, but I had to rebuild all of my images after reverting from SquareThumb and all the images were still of bad quality. I was able to fix those images by going into each album, changing the default picture to something new then changing it back.