District 9 Takes over the Box Office The weekend B.O. provided prima facie evidence that movies tailored to a specific demo can shine in the summer frame, which has historically been dominated by all-audience event pics. Fueled by older males, Sony/TriStar's sci-fi thriller "District 9" opened to a boffo $37 million from 3,049 theaters to win the weekend crown at the domestic B.O. Movie was a sizable victory for Sony's Worldwide Acquisitions Group, Sony's marketing team, frosh filmmaker Neill Blomkamp and producer Peter Jackson. "District's" opening is one more example of a pic generating strong biz this summer without big stars. Coming in a handy No. 2 was Paramount holdover "G.I. Joe: The Rise of Cobra," another male-driven film. "Cobra" dropped 59% to an estimated $22.5 million from 4,007 runs for a domestic cume of $98.8 million. The distaff side of the multiplex was much the same story. Warner Bros./New Line's "The T