erratic album art in music player

so i added album art to most of the mp3s i've got on my galaxy and started the music player
i had to wait a while for the player to index all the files and i had to start playing a track from each of the albums for the cover art to update

i later added a couple more albums to the phone (via usb) and the player had to index everything all over again, only this time it doesn't recognize a lot of the album art it did previously?

what's up with that?

i'm still on ig9; does it work better on newer firmware? (any word on when a new one is released? i5 is still the newest, right?)