Like its predecessor, the first in what will surely grow into a moneymaking franchise spun off from Jeff Kinney’s hilarious stick-figure chronicles of pre-teen agony, part deux of Diary of a Wimpy Kid chugs along inoffensively enough. But shifting from the original’s focus on the experiences of Greg Heffley (Zachary Gordon) at the ignored-runt end of middle school to domestic tyranny at the hands of his bullying big brother (Devon Bostick, a fledgling Jeff Goldblum) is ill-advised. Out come the dusty old tropes: Parents (Steve Zahn and Rachael Harris, mugging obediently) take off for the weekend; place gets trashed; brothers bond over household repair; spend mishap-filled quality time with Grandpa; regress briefly; then re-bond. The truth is that the Diary of a Wimpy Kid series—a chain of comic-book vignettes brilliantly observed from the point of view of a hubris-laden pubescent—was never meant to be plotted or taken live. Director David Bowers (Flushed Away), working from a pretty good screenplay by Gabe Sachs and Jeff Judah, plows ahead valiantly but for far too long before the obligatory school-talent-show finale heaves into view. One consolation: Robert Capron, as the chubby best friend who insists on being a kindly kid instead of a media-savvy twerp.