If a signature sheet of a petition is not certified by the circulator as required under ORS § 198.430, 198.750, 221.031, 248.008, 249.061, 249.740, 249.865, 250.045, 250.165, 250.265, 255.135, 261.115 and 545.025, signatures contained on the signature sheet may not be counted for purposes of determining whether the petition contains the required number of signatures of electors. [2007 c.848 § 8b]