Perhaps you have to help WMP a little bit.
Delete the folder %localappdata%\Microsoft\Media Player\Grafikcache
and see if WMP now updates the image.
Here is a thread on problems with VLC player:
Perhaps you have to help WMP a little bit.
Delete the folder %localappdata%\Microsoft\Media Player\Grafikcache
and see if WMP now updates the image.
Here is a thread on problems with VLC player: