LOS ANGELES (Reuters) - Pop sensation Justin Bieber flew from Europe back to his Los Angeles area home on Tuesday and into an argument with one of his neighbors - the latest in a series of odd incidents involving the teen singer. Deputies were called to the 19-year-old's house in Calabasas, California, on Tuesday morning after a neighbor claimed that he had been threatened and struck by Bieber, said Los Angeles County Sheriff's spokesman Steve Whitmore. A police report alleging battery and threats by Bieber had been filed and was being investigated, Whitmore said. ...