No, but I have seen the theory that Grandpa Dunham is actually Zero's daddy, by a black mommy he met through his friendship with Frank Marshall Davis.
A cockamamie theory to be sure, but nevertheless a highly amusing fantasy.
Such a theory has one advantage. Namely, that at least the father would have been living at the address listed in the announcements. As matters stand, neither the father, the mother nor the baby ever lived there. An honest anti-birther would admit that this is a problem. But I have yet to meet a single honest anti-birther.