Ruh-roh! Romething's really wrong with this ricture! The live-action adventure Scooby-Doo is founded on a love-it-or-hate-it (and you know who you are) pop cultural phenomenon, the long-running Hanna-Barbera cartoon in which four high-decibel young people and a talking, high-maintenance dog solve mysteries and eat snacks. No surprises there. But garbled in the translation is a sense of whether this manic production is meant for pre-ironic kids or an older, more sophisticated audience: The antics involving ghosts, chases, and burping that divert the small fry don't mix with the jokey, tribute-band dialogue spouting from the Mystery, Inc. gang. (Celebrity Scooby-philes include Sarah Michelle Gellar, Freddie Prinze, Jr., and Matthew Lillard in full doofus mode as Shaggy.) The whole enterprise, you might say, is cranked up to a squealing pitch somewhere between ''Zoinks'' and ''Relp!''