United States v. Lopez-Perera, ___ F.3d ___ (9th Cir. Feb. 21, 2006) (physical presence in a port of entry does not satisfy the element of the crime of being illegally or unlawfully in the United States required to constitute the offense of possession of a firearm by a person "illegally or unlawfully in the United States").
http://caselaw.lp.findlaw.com/data2/circs/9th/0550102p.pdf