Last fall Liza Minnelli, Shelley Winters, and the rest of the cast hit the talk- show circuit to enthuse about the fun they had making this musical. Too bad Stepping Out, which started life as a stage play in London and then ran briefly on Broadway, isn’t more fun to sit through. Minnelli sings and hoofs her way through some good old-fashioned musical numbers written by John Kander and Fred Ebb (New York, New York), but the movie trips up on a dull, cliché-heavy story. Minnelli, in an easy, toned-down performance, is a small-time dance teacher saddled with a class full of losers: a brow-beaten housewife, a snooty matron, etc. They put on a show and realize their potential and cry and hug. Liza fans, go back to the Cabaret instead.