important question

There are several different factors at play here. The length of time the adoption has been finalized. What state you're in and the time frames they allow. There are so many factors and it's a long shot.

It would be rare for an adoption to be contested after finalization. If an appropriate agency/attorney took the signing of the surrender documents, if both biological parents have been properly notified, if both bio parents were not under duress, etc., then it would be very, very rare. Birth father issues would most likely be involved and, even at that, he would have to prove that he knew nothing of the pregnancy (where as he for 9 mos.?), that he provided APPROPRIATE financial, physical and emotional support, etc. We had a contested adoption with a bio father who suddenly said he wanted to parent, but he did not file the appropriate documents at the appropriate times and we prevailed. I can't tell you, though, that it wasn't the most difficult time of our lives.

If fraud is alleged, it can be contested. This adoption was finalized, but federal laws were allegedly not followed.[url=http://news.adoption.com/out/legal-adoption-overturned-family-must-surrender-baby-to-indian-tribe-1]Adoption.com - Legal adoption overturned. Family must surrender baby to Indian tribe.[/url]

This was disrupted PLACEMENT, not adoption. No report has ever claimed that finalization actually occurred.

when you both birthparents have been properly notified, is the punative father registry considered properly notified?

That depends on where you live. In some states, it is. In some states, it is not.