Items dissapear after being punched out of Item Frames

After putting some items in some Item frames(Music discs and a diamond block), I punched them out to retrieve them. But, after about 1/4 of a second, they disappeared. Upon searching the area, I found the diamond block and one of the 6 music discs ~15 blocks away, all in different places. I have yet to find the other 5 discs.