change default apple id user name

My 11 year old son has an itouch. I monitor his apps/music so he uses my apple id and password. I have changed my old aol account apple id to a newer one. I have gone into his settings and changed the apple id and logged successfully onto my Itunes account from his Itouch. However whenever he wants to update an app he gets a popup with the old apple id asking for a password. I have synched his itouch while logged in the the proper apple id and nothing seems to make a difference.

Any thoughts, he is super frustrated about not being able to update his apps!