toy story toons unable to redownload

Hi

I bought two toy story toons short movie Small Fly and Hawaiina Vacation during iTune 12 Days of Christmas sale.

Now I try to redownlaod it again into my iPhone/iPad it does not work, and if I try to "insttall" it thrugh iTune, it said cannot be copied.

Does anyone else has the same problem?

Both movie is in my compuer.

Thanks and Regards,

Stephen