United States v. Pettiford, 101 F.3d 199, 200-202 (1st Cir. 1996); United States v. Bacon, 94 F.3d 158, 161 n.3 (4th Cir. 1996); United States v. Cox, 83 F.3d 336, 339-340 (10th Cir. 1996); United States v. Nichols, 30 F.3d 35, 36 (5th Cir. 1994) (government conceded Custis allowed defendant to reopen sentencing); United States v. LaValle, 167 F.3d 1255 (9th Cir. 1999); cf. United States v. Fondren, 54 F.3d 533, 535 (9th Cir. 1995).