The poor-man's Clifton Chenier two-steps with his left foot this time: The opening cut on Five Card Stud is a weak cover of the Bruce Channel oldie ''Hey! Baby.'' And truth to tell, this party never gets cooking, despite Buckwheat Zydeco's flashy accordion licks, vocal trills, and a guest shot by Willie Nelson. Only ''IRS,'' a runaway train of a ditty, and a late-night slow dance called ''Secret of Love'' raise this-barely-above the ordinary. C

