DJ Hero quickplay some songs arent there?

I played the song with rihanna disturbia vs killers somebody told me, anyway i beat it in the career or setlist w/e. so later i went to play it in quickplay by it's self and it's not on the list. why is this? but in the setlist i played it on it says 4 stars beaten... help

better borad for the dj hero --->http://www.gamefaqs.com/boards/gentopic.php?board=954829