On the heels of news that Janet Jackson quit ABC's Lena Horne biopic, the singer's Boobygate costar, Justin Timberlake, has backed out of cohosting ABC's upcoming Motown 45 special. However, his reps insist the move was not more fallout from his now-legendary Super Bowl duet with Jackson. The special apparently conflicts with production of Timberlake's feature film debut, Edison.