(FILES) This picture taken on March 5, 2

(FILES) This picture taken on March 5, 2009 shows US popstar Michael Jackson addressing a press conference at the O2 arena in London. Michael Jackson has pushed back the first four of his comeback concerts in London this year, organisers said on May 20, 2009, but they stressed the decision was not linked to his health. The first scheduled show on July 8 at London’s O2 arena will now take place on July 13. AFP PHOTO/Carl de Souza (Photo credit should read CARL DE SOUZA/AFP/Getty Images)