Organizers of the much hyped Taco Bell One-on-One Championship between NBA stars Hakeem Olajuwon and Shaquille O'Neal canceled the Sept. 30 event after Mr. Olajuwon suffered an injury while working out. A Taco Bell spokeswoman said the company doesn't know whether the bout will be rescheduled, but event organizers said NBA training camp commitments made rescheduling ``nearly impossible.''