I see you have juanes inside there, good choice !
Well let me tell you that this happened to me but only with one folder (the way I setup my music is an artist folder and then inside every album that this artist have.
What I did was to delete one of the folders and the problem desapear (it only happened with that artist) so I put the folder back and it shift all the folders to the right again.... crazy!! I don't know what the deal was but I end up putting the songs for that particular album inside other album folder (even if the song didn't correspond to that album)
So best advice: look for that folder that is mess up. (start for the last one)