I have been divorced since 1999, My ex claims one child and I claim the other, (if and when his childsupport is paid in full) is stated some how in the decree. He has sent the form 8332 and is demanding that I sign it. He shows paid up in the court house although him and I both know better. Am I required to sign this for him?

You need to know what is stated in the divorce decree, the exact wording. That can only be changed by another Court Order.

We need to know specifically what is written.