Now we know why Elton John needed that pacemaker. Two days before his dizzy spell while playing tennis in Nice, he surprised guests at a charity ball in his Windsor home by dancing in public for the first time in years. Twenty cast members from the new, high-energy, ballroom show, Burn the Floor, had just finished entertaining Liz Hurley, Mick Jagger, Jerry Hall, Fergie, Sporty and Baby Spice, when the sultry Latin American champ Tonia Kosovich decided the rocket man could do with a quick blast around the dance floor.