Fox has refused to allow That '70s Show star Ashton Kutcher to appear in a May sweeps celebrity edition of Who Wants to Be a Millionaire. Apparently, Kutcher was originally OK'd to face quizmaster Regis Philbin — provided that his episode not air on a Tuesday night opposite That 70's Show. But Fox suddenly withdrew its consent on Thursday, just one day before Kutcher's Millionaire taping. To appease its star, Fox will donate $32,000 to the University of Iowa's support center for families of transplant patients — that's where Kutcher planned to donate his prize money, since his brother is a heart transplant recipient.