Cheers Star Joins Dancing Competition.... Former Cheers star John Ratzenberger has signed up for reality TV show Dancing With The Stars.Ratzenberger, who played Cliff Clavin on the popular sitcom for 11 seasons, is replacing actor Vincent Pastore.Pastore dropped out of the competition last week (begs26Feb07), claiming the intense training for the show was too physically demanding.The show's producer, Conrad Green, tells American publication People, "Vincent just turned 60 and he had a heart condition last year."Once he started training he said, 'Wow. What have I got myself into?'" Despite only having three weeks to rehearse for the show's 19 March premiere, Ratzenberger insists he will be ready to compete.His representative adds, "He likes to cut a rug. People will be surprised."The 59-year-old joins fellow cast members including Heather Mills, Joey Fatone, Ian Ziering, Billy Ray Cyrus and Paulina Porizkova.