Some Texas stations drop Dixie Chicks tunes 03/15/2003 By DIANA HEIDGERD / The Associated PressDALLAS — When it comes to President Bush, the Dixie Chicks are singing a different tune. But not every country radio station is playing it.Natalie Maines, the Grammy Award-winning group's lead singer, apologized Friday for her criticism of President Bush and possible war against Iraq. That didn't stop some stations in Texas and other parts of the country from pulling Dixie Chicks songs off their programs.Radio stations started getting angry calls from listeners after Maines told a London audience Monday, "Just so you know, we're ashamed...