It appears as if not everyone in Michael Jackson's family is excited about the late singer's upcoming album.  Insiders tell TMZ.com that Jackson's children -- Paris and Prince -- believe that some of the tracks on Sony's record don't actually feature their father's voice.  Sony reportedly believes Jackson is behind all the vocals on the album.  Howard Weitzman, the attorney for Jackson's estate, says experts have listened to the album and are confident that it is in fact the King of Pop's voice.  Other members of the Jackson family are said to be concerned with the validity of the album, but a lawsuit doesn't appear to be on the horizon.  Sony's album, which will feature some of Michael Jackson's unreleased work, is expected to be released by the Christmas holidays.