Disney Channel’s TV movie Phineas and Ferb: Across the 2nd Dimension,” an offshoot from the channel’s successful series, averaged 7.6 million viewers in its debut last night to become the most-watched cable movie of the year. The film also ranked as the No. 1 scripted telecast of 2011 in kids 6-11 (3.4 million) and tweens 9-14 (2.6 million). It became the most-watched cable animated telecast in kids 6-11 and tweens in more than three years, since Fairly OddBaby in February 2008.