AFTER WEEKS of embarrassing headlines about leads flubbed by the FBI and the CIA, followed by the revelation that a government loan officer had conducted a lengthy interview with chief-9/11-hijacker-to-be Mohammed Atta straight out of “Saturday Night Live”–she never got suspicious though he first refused to deal with “but a female,” sang the praises of Osama bin Laden, and playfully suggested cutting her throat–yesterday’s news of the arrest of Abdullah Al Mujahir came as something of a relief. It appears we can occasionally capture a bad guy after all.