first of all let me say welcome, you're obviously new and don't ask me why
in xterm type : df -h
you'll notice full rootfs and maybe full /opt, so you'll have to remove some applications/games and free some space then your music and pics will be available again.
N.B: by space you need to free i don't mean the MyDocs space where you put your music and pics..i mean the space where the apps/games are installed.