Description:
------------
If file A or file B has UTF-8 encoding then you will get the error:

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at index.php:1) in session.php on line 3

Using UTF-8 encoding WITHOUT BOM (Byte Order Mark) seems to fix the problem.

Reproduce code:
---------------
File A:

<?php

include("session");

?>

File B:

<?php

session_start();

?>

Expected result:
----------------
Session is created.

Actual result:
--------------
Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at index.php:1) in session.php on line 3