In light of this court’s recent decision in Simpson v. Norris, 490 F.3d 1029, 1034-1036 (8th Cir. 2007) (concluding the existence of an Arkansas statute that precluded the execution of the mentally retarded was irrelevant to whether the applicant had defaulted an Atkins v. Virginia, 536 U.S. 304, 321, 122 S.Ct. 2242, 153 L.Ed.2d 335 (2002), claim by failing to bring the claim under the statute), reh’g en banc denied, 499 F.3d 874 (8th Cir. 2007), we reverse and vacate the judgment of the district court and remand this case to the district court for further proceedings. See Simpson, 490 F.3d at 1035-36.