Hey Sakya! There's a question I've been meaning to ask you

Not all the album art images of my mp3s appear in the album art area of the lockscreens. I have checked that all my mp3s have album covers (embeded) and they all appear in both default media player and Someplayer.

For example, I have three mp3s tagged with the same album art (everybody hurts, man on the moon and drive from REM's automatic for the people) and only one of them shows the cover (everybody hurts)

Any idea why this is happening?