sigue saliendo el error pero en vez de indicar la linea 2 indica la 1.
Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at C:\AppServ\www\museo\admin\noticias.php:1) in C:\AppServ\www\museo\admin\sesion.php on line 1
Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at C:\AppServ\www\museo\admin\noticias.php:1) in C:\AppServ\www\museo\admin\sesion.php on line 1
el sesion.php lo puesto asi: