Here is a reference for you.
Oregon statutes comply with these requirements. Under ORS 109.070(2), a party to a
Voluntary acknowledgment of paternity may rescind it within the earlier of 1) sixty days after the
Acknowledgment was filed or 2) the date an order in a proceeding relating to the child, including
A proceeding to establish a support order, was entered. Under ORS 109.070(3), a voluntary
Acknowledgment may be challenged in circuit court on the basis of fraud, duress or material
Mistake of fact at any time by a party to the acknowledgment, the child or the Department of
Human Services or the administrator of the child support enforcement program if the child is in
The care and custody of DHS as a dependent child under ORS 419B and the department or the
Administrator reasonably believes that the acknowledgment was obtained through fraud, duress
Or a material mistake of fact. Subsection (3) also allows a challenge to be brought in circuit court
For up to one year, unless ORS 109.070(4)(a). Subsection (4)(a), in turn, allows a party or the
State, if child support enforcement services are being provided and if blood testing has not been
Done, to apply to the child support administrator or the court for an order for blood testing for up
To one year after the acknowledgment was signed. If the blood tests exclude the man as the
Child’s biological father, a party or the state may apply to the court for a judgment of
Nonpaternity. The paternity that receives this judgment must send it to the state office of vital
Records so that the child’s birth records can be corrected.
http://search.yahoo.com/r/_ylt=A0oG7...2382report.pdf
Disestablishing Paternity After 13 Years in Oregon