It looks like when a sprite/image doesn't occupy all the space assigned to it in memory, it's dumped with left over gibberish from previous draw calls, which causes most character images and interface elements to be dumped every frame and thus make replacement impossible.
A single image being dumped several times because the pixel column to the right is filled with gibberish that causes the image to be dumped every time the emulator encounters it.
It looks like when a sprite/image doesn't occupy all the space assigned to it in memory, it's dumped with left over gibberish from previous draw calls, which causes most character images and interface elements to be dumped every frame and thus make replacement impossible.
A single image being dumped several times because the pixel column to the right is filled with gibberish that causes the image to be dumped every time the emulator encounters it.