Este es el problema:

Warning: move_uploaded_file(): open_basedir restriction in effect. File(/home/webcindario/Beti-Stadio/phpBB2/tmp/phpSnBZCt) is not within the allowed path(s): (/home/webcindario/beti-stadio) in /home/webcindario/beti-stadio/phpBB2/includes/usercp_avatar.php on line 110

En la linea 110 tengo puesto esto:

move_uploaded_file($avatar_filename,'/home/webcindario/Beti-Stadio/phpBB2'.$avatar_filename);

Este es el codigo completo:

if ($avatar_mode == 'local') {
move_uploaded_file($avatar_filename,'/home/webcindario/Beti-Stadio/phpBB2'.$avatar_filename);
$avatar_filename ='/home/webcindario/Beti-Stadio/phpBB2'.$avatar_filename;
}
$tmp_path ='/home/webcindario/beti-stadio/phpBB2/tmp';