SONS OF TUCSON. 9:30 p.m. Sunday, Channel 29.

"I'M SEEING butt crack. Are we this desperate?" asks the angel-faced youngest, Robby (Benjamin Stockham), Sunday in "Sons of Tucson," Fox's latest attempt to find a live-action family comedy that can keep up with its animated ones.

Hey, I sometimes miss "Malcolm in the Middle," too, but I'm not this desperate.

"Sons," whose producers actually include Justin Berfield, who only looks about five minutes older these days than when he played "Malcolm's" brother Reese, isn't in that league. Smart-mouthed kids just aren't enough.

Tyler Labine ("Reaper"), who seems to be becoming the poor man's Jack Black, stars as a debt-ridden slacker who's living in his car and who gets hired by three young brothers to impersonate their father at a meeting at their school. Their real father's in jail and they've made their way from New Jersey to Arizona, where he had some property, and are living on their own, without parental supervision or, apparently, any financial problems.

With all due respect to the young actors playing them, who can only say the words the writers put in their mouth, these are three of the least appealing sitcom kid characters I've seen in a while, and though Labine's made me laugh in the past as a secondary character, as a lead he's leaden.