There's something funny about Martin Lawrence, and it's not his unstinting, hit-or-miss patter or his jerky physicality, which wastes more energy than the Cheney energy task force. No, the funny thing about Lawrence is he's often paired with a partner (e.g., ''Blue Streak,'' ''Bad Boys,'' etc.), yet has no aptitude for sharing the screen.
Playing overzealous security guard Earl Montgomery in National Security, he stubbornly refuses to jell with Steve Zahn's stolid patrolman, who's tossed off the force on Earl's trumped-up brutality charge. (The two muster enough racial harmony to hunt up some stolen beer kegs made of space-age alloy -- yup, you read that right.) Zahn, strapped to the straight-man gurney, looks perpetually on the verge of an aneurysm, relieved only by periodic slo-mo shootouts that set a new standard in post-Michael Bay preposterousness.