Comedy director Carl Reiner is at his lowest ebb in this threadbare effort, scripted by Martha Goldhirsh, about an uptight married older sister (a frenetic Kirstie Alley) and a flaky and footloose younger one (Jami Gertz)derived, it would seem, from the sisters in sex, lies, and videotape. By overwhelming coincidence number one, the older sister has an unprecedented sexual fling with a stranger (Sam Elliott)her husband’s brother as it turns out, expected for dinner that very nightwho then dies of a heart attack; by overwhelming coincidence number two, after the brother’s corpse is discovered by a blinds salesman (a very unfunny Bill Pullman), the salesman’s cop brother (Ed O’Neill) investigates the case and winds up making a match with the flaky sister. Reiner chugs through it all as if he had his mind on something else, as well he should have. (JR)