PROCOL'S NINTHFor their ninth album, Procol Harum turned to production by the veteran songwriting team of Leiber and Stoller, who had written the first single ("Poison Ivy") by Procol predecessor band, the Paramounts. Though the band is in top form (especially drummer B. J. Wilson) and despite a strong start (with the exquisite "Pandora's Box," a U. K. hit), the album largely runs out of steam by side two. Too much of the Brooker and Reid material is competent